Biodiversity & Conservation

Topic: Loss of Biodiversity; Subtopic: Causes and Conservation Methods

Keyword Definitions:

• Biodiversity: The variety of life forms on Earth, including plants, animals, microorganisms, and the ecosystems they form.

• Ex situ conservation: The conservation of species outside their natural habitats through methods like zoos, seed banks, and cryopreservation.

• The Evil Quartet: The four major causes of biodiversity loss — habitat loss, overexploitation, alien species invasion, and co-extinction.

• Alien species: Non-native species introduced into a new habitat, often causing ecological imbalance.

• Extinction: The complete disappearance of a species from Earth due to natural or human-induced causes.

Lead Question - 2025

Match List-I with List-II :

List-I      List-II
A. The Evil Quartet      I. Cryopreservation
B. Ex situ conservation      II. Alien species invasion
C. Lantana camara      III. Causes of biodiversity loss
D. Dodo      IV. Extinction

(1) A-III, B-II, C-I, D-IV
(2) A-III, B-I, C-II, D-IV
(3) A-III, B-IV, C-II, D-I
(4) A-III, B-II, C-IV, D-I

Explanation: The Evil Quartet represents four main causes of biodiversity loss. Ex situ conservation includes cryopreservation, seed banks, and botanical gardens. Lantana camara is an example of alien species invasion, while the Dodo is an extinct bird species from Mauritius. Therefore, the correct matches are A-III, B-I, C-II, D-IV. Answer: (2) A-III, B-I, C-II, D-IV

1. Which of the following is not a part of the Evil Quartet?
(1) Habitat loss
(2) Overexploitation
(3) Global warming
(4) Alien species invasion
Explanation: The Evil Quartet consists of four main causes of biodiversity loss: habitat loss, overexploitation, alien species invasion, and co-extinction. Global warming, though significant, is considered an indirect contributor to biodiversity decline, not part of the original Evil Quartet. Answer: (3) Global warming

2. The extinct bird Dodo was endemic to which island?
(1) Mauritius
(2) Madagascar
(3) Seychelles
(4) Galápagos Islands
Explanation: The Dodo was endemic to Mauritius and became extinct in the 17th century due to human hunting and introduction of invasive animals like rats and pigs. It symbolizes the irreversible loss caused by human interference with natural ecosystems. Answer: (1) Mauritius

3. Which among the following is a method of ex situ conservation?
(1) Biosphere reserves
(2) National parks
(3) Gene banks
(4) Wildlife sanctuaries
Explanation: Gene banks are a form of ex situ conservation where genetic materials such as seeds, gametes, or embryos are stored under controlled conditions. This ensures the preservation of species outside their natural habitat for future restoration. Answer: (3) Gene banks

4. Which of the following invasive species has affected Indian forests the most?
(1) Eichhornia crassipes
(2) Lantana camara
(3) Prosopis juliflora
(4) Opuntia monocantha
Explanation: Lantana camara, an ornamental shrub introduced from America, has invaded Indian forests, suppressing the growth of native plants. It alters forest ecology and reduces biodiversity significantly. Answer: (2) Lantana camara

5. In situ conservation refers to:
(1) Protection of species in their natural habitat
(2) Protection of species outside their habitat
(3) Storage of seeds under low temperatures
(4) Breeding of animals in captivity
Explanation: In situ conservation involves protecting and maintaining species in their natural habitats, such as biosphere reserves, national parks, and wildlife sanctuaries. It ensures the continuity of evolutionary processes. Answer: (1) Protection of species in their natural habitat

6. Which of the following is an example of ex situ conservation?
(1) Sacred groves
(2) National parks
(3) Zoological parks
(4) Biosphere reserves
Explanation: Zoological parks are examples of ex situ conservation, where animals are maintained in controlled environments outside their natural habitats for breeding, research, and education purposes. Answer: (3) Zoological parks

7. Assertion-Reason Type:
Assertion (A): Habitat destruction is a major cause of species extinction.
Reason (R): Conversion of forests into agricultural land reduces the natural habitat of many species.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Habitat destruction due to deforestation and agricultural expansion reduces available space and resources for native species, causing population decline and extinction. Both statements are true, and R correctly explains A. Answer: (1) Both A and R are true, and R is the correct explanation of A

8. Matching Type:
Match the following conservation methods with their examples:
A. In situ — I. National Park
B. Ex situ — II. Seed Bank
C. Sacred grove — III. Traditional conservation
(1) A-I, B-II, C-III
(2) A-II, B-I, C-III
(3) A-I, B-III, C-II
(4) A-III, B-I, C-II
Explanation: In situ conservation includes protected areas like national parks. Ex situ conservation includes seed banks and zoos. Sacred groves represent ancient traditions of conserving biodiversity through cultural reverence. Answer: (1) A-I, B-II, C-III

9. Fill in the Blanks:
_________ refers to the storage of seeds or gametes at very low temperatures for long-term preservation.
(1) Biosphere reserve
(2) Cryopreservation
(3) Afforestation
(4) Gene editing
Explanation: Cryopreservation involves storing biological materials such as gametes, seeds, or tissues at extremely low temperatures, typically using liquid nitrogen. This technique helps preserve endangered species' genetic resources for future recovery. Answer: (2) Cryopreservation

10. Choose the Correct Statements:
Statement I: Ex situ conservation includes zoological parks and seed banks.
Statement II: The Evil Quartet represents conservation methods.
(1) Both statements are correct
(2) Only Statement I is correct
(3) Only Statement II is correct
(4) Both statements are incorrect
Explanation: Ex situ conservation involves preserving species outside their natural habitats, such as in seed banks and zoological parks. The Evil Quartet refers to causes of biodiversity loss, not conservation. Hence, only Statement I is correct. Answer: (2) Only Statement I is correct

Topic: Methods of Biodiversity Conservation; Subtopic: Ex-situ and In-situ Conservation

Keyword Definitions:
• Biodiversity: The variety of living organisms found in a specific habitat or on Earth.
• Conservation: The sustainable management of natural resources to prevent depletion.
• In-situ Conservation: Protecting species within their natural habitats.
• Ex-situ Conservation: Conserving species outside their natural habitats through zoos, botanical gardens, or gene banks.
• Protected Areas: Regions legally designated for wildlife protection such as national parks and sanctuaries.

Lead Question – 2025
Which one of the following is an example of ex-situ conservation?
(1) National Park
(2) Wildlife Sanctuary
(3) Zoos and botanical gardens
(4) Protected areas

Explanation:
Ex-situ conservation involves the preservation of species outside their natural habitats, allowing scientific study and controlled breeding. Zoos and botanical gardens serve as important ex-situ conservation sites. They protect endangered species, maintain genetic diversity, and support reintroduction programs. In contrast, national parks and sanctuaries represent in-situ conservation. Therefore, the correct answer is (3) Zoos and botanical gardens.

Guessed Questions:

1. Single Correct Answer:
Which of the following represents in-situ conservation?
(1) Cryopreservation
(2) Seed banks
(3) Biosphere reserves
(4) Tissue culture
Explanation:
In-situ conservation preserves organisms within their natural habitats, maintaining ecological balance. Biosphere reserves are large areas where biodiversity is conserved while allowing sustainable resource use by humans. Cryopreservation and seed banks are ex-situ methods. Thus, the correct answer is (3) Biosphere reserves.

2. Single Correct Answer:
Which of the following is not an ex-situ conservation method?
(1) Gene banks
(2) National parks
(3) Botanical gardens
(4) Zoological parks
Explanation:
Ex-situ methods include conservation of species outside their natural habitats such as gene banks, zoos, and botanical gardens. National parks conserve species in their natural ecosystems, thus representing in-situ conservation. Hence, the correct answer is (2) National parks.

3. Single Correct Answer:
Cryopreservation of gametes of endangered species is an example of:
(1) In-situ conservation
(2) Ex-situ conservation
(3) Habitat protection
(4) Natural regeneration
Explanation:
Cryopreservation involves storing gametes or embryos of endangered species at ultra-low temperatures, preventing genetic loss and aiding reproduction later. This process is done outside the organism’s natural environment, making it an ex-situ conservation method. Therefore, the correct answer is (2) Ex-situ conservation.

4. Single Correct Answer:
Which of the following organizations maintains seed banks globally?
(1) WHO
(2) FAO
(3) UNESCO
(4) IMF
Explanation:
The Food and Agriculture Organization (FAO) plays a key role in maintaining global seed banks, ensuring the preservation of crop diversity. These seed banks safeguard genetic material essential for breeding and food security. Hence, the correct answer is (2) FAO.

5. Single Correct Answer:
The concept of gene banks is used in:
(1) Ex-situ conservation
(2) In-situ conservation
(3) Reintroduction programs
(4) Population estimation
Explanation:
Gene banks store genetic material such as seeds, pollen, or DNA samples for future use. They preserve biodiversity outside natural habitats, aiding genetic studies and restoration efforts. Therefore, gene banks are examples of ex-situ conservation. The correct answer is (1) Ex-situ conservation.

6. Single Correct Answer:
Which of the following is a drawback of ex-situ conservation?
(1) Species protection from predators
(2) Natural behavior loss due to captivity
(3) Controlled breeding
(4) Genetic diversity maintenance
Explanation:
While ex-situ conservation protects species from immediate extinction, it often leads to loss of natural behaviors and reduced adaptability in captivity. Animals in zoos may not fully exhibit survival instincts when reintroduced into the wild. Hence, the correct answer is (2) Natural behavior loss due to captivity.

7. Assertion–Reason Type:
Assertion (A): Ex-situ conservation helps preserve endangered species.
Reason (R): It maintains species only in their natural environment.
(1) Both A and R are true, and R explains A
(2) Both A and R are true, but R does not explain A
(3) A is true, R is false
(4) A is false, R is true
Explanation:
Ex-situ conservation protects endangered species by maintaining them outside their natural environments in artificial conditions. The reason given is incorrect because ex-situ occurs outside natural habitats. Thus, A is true but R is false. The correct answer is (3) A is true, R is false.

8. Matching Type:
Match the following:
List I (Conservation Method) – List II (Example)
A. Ex-situ – (i) Zoos
B. In-situ – (ii) National Parks
C. Cryopreservation – (iii) Frozen gametes
D. Seed Bank – (iv) Genetic conservation
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-i, C-iii, D-iv
(3) A-iv, B-iii, C-i, D-ii
(4) A-i, B-iii, C-iv, D-ii
Explanation:
Zoos represent ex-situ, national parks represent in-situ, cryopreservation stores gametes frozen, and seed banks maintain genetic material for conservation. Hence, the correct match is (1) A-i, B-ii, C-iii, D-iv.

9. Fill in the Blanks:
__________ conservation is practiced by maintaining species in artificial conditions outside their natural habitat.
(1) In-situ
(2) Ex-situ
(3) Natural
(4) Wild
Explanation:
When organisms are maintained in controlled artificial conditions such as zoos or botanical gardens for preservation, it is termed ex-situ conservation. This allows scientists to manage breeding and protect endangered species. Hence, the correct answer is (2) Ex-situ.

10. Choose the Correct Statements:
Statement I: Seed banks and zoos represent ex-situ conservation.
Statement II: National parks and sanctuaries are examples of in-situ conservation.
(1) Both are true
(2) Both are false
(3) I is true, II is false
(4) I is false, II is true
Explanation:
Ex-situ conservation includes zoos, seed banks, and gene banks; in-situ includes sanctuaries and parks where species live in their natural ecosystem. Both statements are correct representations of their types. Therefore, the correct answer is (1) Both are true.

Topic: Sacred Groves and Biodiversity Hotspots; Subtopic: Role of Traditional Conservation Practices in Biodiversity Preservation

Keyword Definitions:

• Sacred Groves: Small forest patches protected by local communities due to religious or cultural beliefs, serving as biodiversity reservoirs.

• Biodiversity Hotspot: A region with high species richness and endemism under significant threat from human activities.

• In-situ Conservation: The preservation of species in their natural habitats such as national parks, wildlife sanctuaries, and sacred groves.

• Endemism: The ecological state of species being unique to a defined geographic location.

• Ecological Balance: The stability maintained among organisms and their environment to sustain natural systems.

Lead Question - 2024 (Jhajjhar)
Identify the place(s) from the following where sacred groves are not found.
A. Aravalli Hills of Rajasthan.
B. Chanda and Bastar area of Madhya Pradesh.
C. Mudumalai Sanctuary in Tamil Nadu.
D. Khasi and Jaintia Hills in Meghalaya.
Choose the correct answer from the options given below:
1. A only
2. C only
3. B and C only
4. C and D only

Explanation: Sacred groves are present in the Aravalli Hills, Chanda and Bastar regions, and in the Khasi and Jaintia Hills due to deep-rooted cultural and spiritual beliefs. However, Mudumalai Sanctuary in Tamil Nadu is a protected reserve, not a sacred grove area. Hence, the correct answer is C only. Sacred groves play a vital role in conserving rare plant and animal species.

Guessed Questions:

1. Which of the following best describes sacred groves?
1. Areas used for agricultural expansion
2. Protected patches of forests preserved due to religious beliefs
3. Government-owned forest reserves
4. Urban botanical gardens
Explanation: Sacred groves are forest patches protected by local communities due to traditional and religious significance. These sites act as biodiversity hotspots preserving endemic flora and fauna. They are crucial for in-situ conservation and help maintain ecological stability by safeguarding old-growth vegetation from exploitation.

2. In India, sacred groves are most commonly found in which type of region?
1. Arid plains
2. Forested tribal regions
3. Urban landscapes
4. Agricultural zones
Explanation: Sacred groves are predominantly found in forested tribal regions of India, where indigenous communities protect them due to cultural and spiritual associations. Such groves exist in Meghalaya, Western Ghats, Rajasthan, and Madhya Pradesh, representing ancient ecological traditions ensuring biodiversity conservation and groundwater recharge.

3. Which one of the following states is known for a large number of sacred groves?
1. Punjab
2. Meghalaya
3. Haryana
4. Gujarat
Explanation: Meghalaya has numerous sacred groves maintained by the Khasi and Jaintia tribes. These groves represent a centuries-old conservation method protecting diverse species of plants, birds, and insects. They play an essential role in preserving the ecosystem and serve as reservoirs of genetic diversity for future generations.

4. Sacred groves are an example of which type of biodiversity conservation?
1. Ex-situ conservation
2. In-situ conservation
3. Genetic engineering
4. Afforestation program
Explanation: Sacred groves are classic examples of in-situ conservation because they protect species within their natural habitats. These areas are left untouched by human interference and provide a sanctuary for plants, animals, and microorganisms, ensuring natural evolution, genetic diversity, and ecosystem stability in their native environment.

5. Which of the following tribal groups is associated with the protection of sacred groves in India?
1. Santhals
2. Bhils
3. Khasi
4. Todas
Explanation: The Khasi tribes of Meghalaya are renowned for preserving sacred groves through religious and cultural beliefs. These communities consider such forests as the abode of deities, restricting tree felling and hunting. Their spiritual practices have helped protect biodiversity in these regions for generations, illustrating cultural-based conservation ethics.

6. Which of the following is not a characteristic feature of sacred groves?
1. Areas protected for religious reasons
2. Sites rich in biodiversity
3. Commercial logging allowed
4. Traditionally preserved by local communities
Explanation: Commercial logging is not a feature of sacred groves. These regions are protected primarily for spiritual and cultural reasons, often prohibiting the extraction of timber and hunting. As a result, they maintain ecological balance and protect endemic and rare species naturally, contributing significantly to biodiversity conservation.

7. Assertion–Reason Question
Assertion (A): Sacred groves are biodiversity-rich areas protected by tribal communities.
Reason (R): They are used mainly for commercial forest products.
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Explanation: Assertion is true because sacred groves are conserved by tribal groups for spiritual and ecological reasons. The reason is false because sacred groves are not exploited for commercial products. They are protected zones ensuring natural biodiversity preservation and environmental balance without human interference.

8. Matching Type Question
Match List I with List II:
A. Khasi Hills – I. Meghalaya
B. Aravalli Hills – II. Rajasthan
C. Kodagu District – III. Karnataka
D. Bastar Region – IV. Chhattisgarh
1. A-I, B-II, C-III, D-IV
2. A-II, B-I, C-IV, D-III
3. A-IV, B-III, C-II, D-I
4. A-I, B-IV, C-II, D-III
Explanation: Sacred groves are geographically widespread: Khasi Hills in Meghalaya, Aravalli Hills in Rajasthan, Kodagu in Karnataka, and Bastar in Chhattisgarh. Each region preserves biodiversity through cultural beliefs. The correct match is A-I, B-II, C-III, D-IV, showing the diversity of ecological conservation practices across India.

9 Fill in the Blanks Question
Sacred groves are primarily protected due to ______.
1. Economic importance
2. Religious and cultural beliefs
3. Tourism potential
4. Forest policy enforcement
Explanation: Sacred groves are preserved mainly due to religious and cultural beliefs. Local communities consider them sacred spaces dedicated to deities and ancestors. This spiritual reverence restricts exploitation, leading to the natural protection of diverse flora and fauna, soil fertility conservation, and water retention in the ecosystem.

10. Choose the Correct Statements Question
Statement I: Sacred groves represent an ancient form of biodiversity conservation.
Statement II: Sacred groves are found only in tropical rainforests.
1. Both statements are true.
2. Both statements are false.
3. Statement I is true, Statement II is false.
4. Statement I is false, Statement II is true.
Explanation: Statement I is true as sacred groves are one of the oldest conservation practices in India. Statement II is false because sacred groves are found in various regions, including deserts, hills, and temperate zones. They serve as reservoirs of biodiversity irrespective of climatic conditions.

Topic: Biodiversity Patterns; Subtopic: Loss of Biodiversity and Rainforest Depletion

Keyword Definitions:

• Biodiversity: Variety of life forms at genetic, species, and ecosystem levels.

• Rainforest: Dense, warm, wet forests supporting a wide range of species.

• Amazon Rainforest: World’s largest tropical rainforest located in South America.

• Deforestation: Large-scale clearing of forests mainly for agriculture and human settlement.

• Conservation: Sustainable management of natural resources and ecosystems.

Lead Question – 2024 (Jhajjar)
Given below are two statements:
Statement I: Rain forests which used to cover more than 14% of the earth's land surface is now reduced to 6%.
Statement II: Amazon rain forest has greatest biodiversity on earth.
In the light of the above statements, choose the correct answer from the options given below:
1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true
Answer: Both Statement I and Statement II are true.
Explanation: Tropical rainforests once covered about 14% of Earth's surface but now only about 6% due to deforestation. The Amazon rainforest, the largest of its kind, contains the richest biodiversity on Earth, housing millions of plant, animal, and microbial species, thus supporting Statement I and Statement II as both true.

1. Single Correct Answer Question:
Which of the following regions shows the highest species richness?
1. Polar regions
2. Temperate forests
3. Tropical rainforests
4. Deserts
Answer: Tropical rainforests.
Explanation: Tropical rainforests possess the highest species richness due to stable climatic conditions, high moisture, and ample sunlight that support year-round growth. These regions harbor the maximum number of plant, animal, and microbial species, contributing to global biodiversity conservation and maintaining the ecological balance on Earth.

2. Single Correct Answer Question:
Which of the following is not a cause of biodiversity loss?
1. Overexploitation
2. Habitat destruction
3. Natural selection
4. Invasive species
Answer: Natural selection.
Explanation: Natural selection is a natural evolutionary process that promotes adaptation and survival of the fittest. It does not contribute to biodiversity loss. In contrast, human-induced factors like overexploitation, habitat destruction, and introduction of invasive species severely reduce biodiversity worldwide, causing extinction of many natural species.

3. Single Correct Answer Question:
Which of the following biomes is known for the least biodiversity?
1. Desert
2. Tropical rainforest
3. Coral reef
4. Grassland
Answer: Desert.
Explanation: Deserts have extreme environmental conditions with low rainfall, high temperatures, and scarce vegetation, leading to limited biodiversity. Only highly adapted species can survive there, unlike tropical rainforests and coral reefs that support rich biodiversity due to favorable climatic and nutrient conditions promoting complex ecosystems.

4. Single Correct Answer Question:
Which conservation strategy focuses on maintaining species in their natural habitats?
1. In situ conservation
2. Ex situ conservation
3. Genetic engineering
4. Bioremediation
Answer: In situ conservation.
Explanation: In situ conservation involves protecting species within their natural ecosystems, such as national parks, wildlife sanctuaries, and biosphere reserves. This approach preserves ecological integrity and allows species to continue their evolutionary processes naturally, ensuring sustainable conservation of biodiversity in its original environment.

5. Single Correct Answer Question:
Which of the following is an example of ex situ conservation?
1. National park
2. Zoological park
3. Biosphere reserve
4. Wildlife sanctuary
Answer: Zoological park.
Explanation: Ex situ conservation involves protecting endangered species outside their natural habitats through breeding programs, seed banks, botanical gardens, and zoological parks. Such methods ensure the survival of rare species by maintaining them under controlled conditions, which helps prevent extinction and supports reintroduction in the wild later.

6. Single Correct Answer Question:
Which region is called the “lungs of the planet”?
1. Sahara Desert
2. Amazon Rainforest
3. Arctic tundra
4. Great Barrier Reef
Answer: Amazon Rainforest.
Explanation: The Amazon Rainforest is known as the “lungs of the planet” because it produces about 20% of Earth’s oxygen through photosynthesis. Its vast vegetation absorbs large amounts of carbon dioxide, helping to regulate global climate and maintaining the balance of atmospheric gases essential for life on Earth.

7. Assertion-Reason Question:
Assertion (A): Biodiversity is higher in tropical regions.
Reason (R): Tropical regions have a stable climate and high productivity.
Options:
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Answer: Both A and R are true, and R is the correct explanation of A.
Explanation: Tropical regions support maximum biodiversity due to their stable environmental conditions and high primary productivity. Constant temperature, abundant sunlight, and continuous rainfall encourage species diversification, reproduction, and evolution, making tropical ecosystems the richest in terms of biological diversity on Earth.

8. Matching Type Question:
Match List I with List II:
A. Hotspot of biodiversity – I. Western Ghats
B. Conservation in natural habitat – II. In situ
C. Zoological park – III. Ex situ
D. Convention on biodiversity – IV. 1992
Choose the correct option:
1. A-I, B-II, C-III, D-IV
2. A-II, B-I, C-IV, D-III
3. A-III, B-II, C-I, D-IV
4. A-IV, B-I, C-II, D-III
Answer: A-I, B-II, C-III, D-IV.
Explanation: Biodiversity hotspots like the Western Ghats are regions of exceptional species richness. Conservation in natural habitats refers to in situ methods. Zoological parks are examples of ex situ conservation, while the Convention on Biological Diversity was signed in 1992 to globally protect ecosystems and genetic resources.

9. Fill in the Blanks Question:
The total number of species found on Earth is about __________.
1. 1.5 million
2. 3 million
3. 8.7 million
4. 10 million
Answer: 8.7 million.
Explanation: Scientists estimate that there are approximately 8.7 million species on Earth, including plants, animals, fungi, and microorganisms. However, only about 1.75 million species have been described. This vast biodiversity is distributed unevenly across ecosystems, with tropical regions harboring the majority of species diversity globally.

10. Choose the Correct Statements (Statement I & II) Question:
Statement I: Species diversity decreases as we move from the equator to the poles.
Statement II: This pattern is known as the latitudinal gradient of biodiversity.
1. Both statements are true.
2. Both statements are false.
3. Statement I is true but Statement II is false.
4. Statement I is false but Statement II is true.
Answer: Both statements are true.
Explanation: Biodiversity decreases with increasing latitude due to declining temperatures and shorter growing seasons near the poles. This phenomenon, known as the latitudinal gradient, highlights how tropical regions near the equator support denser and more complex ecosystems compared to temperate or polar environments worldwide.

Subtopic: Patterns of Biodiversity and Conservation Approaches

Keyword Definitions:

• Biodiversity: The variety of living organisms in a particular habitat or on Earth.

• Species–Area Relationship: Describes how species richness increases with area sampled.

• Rivet Popper Hypothesis: A theory suggesting that species are like rivets in an airplane; losing too many weakens the ecosystem.

• Global Species Diversity: The total number of species existing on Earth, estimated to be about 7 million.

• Long-term Ecosystem Experiment: A continuous outdoor study analyzing species interactions and ecosystem stability.

Lead Question (September 2024)
Match List I with List II
List I                                        List II
A. Robert May        I. Species–area relationship
B. Alexander von Humboldt    II. Long-term ecosystem experiment using outdoor plots
C. Paul Ehrlich          III. Global species diversity about 7 million
D. David Tilman       IV. Rivet popper hypothesis

Choose the correct answer from the options given below:
(1) A–III, B–I, C–IV, D–II
(2) A–I, B–III, C–II, D–IV
(3) A–III, B–IV, C–II, D–I
(4) A–II, B–III, C–I, D–IV

Explanation: The correct answer is (1). Robert May estimated global species diversity to be around 7 million. Alexander von Humboldt described the species–area relationship. Paul Ehrlich proposed the rivet popper hypothesis, and David Tilman conducted long-term ecosystem experiments. This question highlights major contributions in biodiversity and ecological studies with real-world conservation relevance.

1. Which scientist proposed the Rivet Popper Hypothesis?
(1) Charles Darwin
(2) Paul Ehrlich
(3) Robert May
(4) David Tilman

Explanation: The correct answer is (2). Paul Ehrlich proposed the Rivet Popper Hypothesis, comparing species in an ecosystem to rivets in an airplane’s wings. Loss of too many species (rivets) destabilizes ecosystem structure and function, emphasizing the importance of maintaining biodiversity and interdependence among species to ensure ecological stability.

2. Who described the species–area relationship?
(1) Alexander von Humboldt
(2) Charles Elton
(3) Robert May
(4) David Tilman

Explanation: The correct answer is (1). Alexander von Humboldt observed that species richness increases with the area sampled, leading to the species–area relationship concept. It shows a predictable pattern of biodiversity distribution and forms the basis for understanding ecological diversity gradients across habitats and regions globally.

3. Assertion–Reason Question:
Assertion (A): Biodiversity ensures ecosystem stability.
Reason (R): Each species contributes uniquely to ecological balance and nutrient cycling.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, but R is false
(4) A is false, but R is true

Explanation: The correct answer is (1). Biodiversity contributes to ecosystem resilience by providing various functional roles. Each species supports ecological balance, nutrient cycling, and energy flow. High biodiversity increases adaptability and reduces vulnerability to disturbances, ensuring the ecosystem’s stability and sustainability over time.

4. Fill in the Blanks:
The total estimated number of species on Earth is approximately __________.
(1) 5 million
(2) 7 million
(3) 9 million
(4) 10 million

Explanation: The correct answer is (2). According to Robert May, global species diversity is about 7 million. However, only around 1.5 million species have been scientifically described. The estimation emphasizes the vast unexplored biodiversity, especially among microorganisms and deep-sea species that are still being discovered.

5. Which of the following best describes the ‘Species–Area Relationship’?
(1) Number of individuals increases with area
(2) Number of species increases with area
(3) Number of species decreases with area
(4) Population density decreases with area

Explanation: The correct answer is (2). The species–area relationship states that larger geographic areas contain more species. It is represented mathematically as S = C·AZ, where S is species richness, A is area, and Z is a constant. This relationship highlights spatial patterns in biodiversity distribution.

6. Choose the Correct Statements:
Statement I: David Tilman’s experiments showed that greater species richness enhances ecosystem productivity.
Statement II: Loss of biodiversity reduces ecosystem stability.
(1) Both statements are correct
(2) Only Statement I is correct
(3) Only Statement II is correct
(4) Both statements are incorrect

Explanation: The correct answer is (1). David Tilman’s long-term experiments confirmed that ecosystems with high biodiversity are more productive and resilient. Biodiversity loss leads to reduced stability and functioning, making ecosystems vulnerable to changes, nutrient loss, and reduced biomass production.

7. Which of the following scientists is correctly matched with their contribution?
(1) Robert May – Rivet Popper Hypothesis
(2) Alexander von Humboldt – Species–Area Relationship
(3) David Tilman – Global Species Estimate
(4) Paul Ehrlich – Long-term Field Experiments

Explanation: The correct answer is (2). Alexander von Humboldt’s pioneering work established the species–area relationship, showing that larger habitats contain more species. His observations laid the foundation for modern ecology and biogeography, influencing later research on species distribution and conservation.

8. Which of the following ecosystems has the highest biodiversity?
(1) Tundra
(2) Desert
(3) Tropical rainforest
(4) Taiga

Explanation: The correct answer is (3). Tropical rainforests have the highest biodiversity due to their warm climate, consistent rainfall, and complex vegetation layers. These conditions support diverse habitats, high productivity, and numerous ecological niches, allowing millions of species to coexist in a single region.

9. Matching Type Question:
Match the following conservation concepts with their examples:
A. In-situ conservation  I. National parks
B. Ex-situ conservation  II. Zoological parks
C. Sacred Groves  III. Community-protected forests
D. Red Data Book  IV. List of threatened species

(1) A–I, B–II, C–III, D–IV
(2) A–II, B–I, C–IV, D–III
(3) A–III, B–IV, C–I, D–II
(4) A–IV, B–III, C–II, D–I

Explanation: The correct answer is (1). In-situ conservation involves protecting species within their natural habitats like national parks. Ex-situ involves preservation outside natural habitats such as zoological parks. Sacred groves represent traditional community-protected forests, and the Red Data Book lists threatened and endangered species globally.

10. Which law is expressed by the equation S = C·AZ?
(1) Hardy–Weinberg Law
(2) Species–Area Relationship
(3) Gause’s Competitive Exclusion Principle
(4) Lotka–Volterra Equation

Explanation: The correct answer is (2). The equation S = C·AZ represents the species–area relationship, where S is the number of species, A is the area, C is a constant, and Z represents the slope. It shows how species richness increases with the sampled area, fundamental to ecological studies.

Topic: Endangered Species; Subtopic: Conservation Organizations

Keyword Definitions:

• Endangered Species: Species at risk of extinction due to habitat loss, hunting, or environmental changes.

• WWF: World Wide Fund for Nature, an international NGO for wildlife conservation.

• IUCN: International Union for Conservation of Nature, publishes Red List of threatened species.

• FOAM: Forum for conservation awareness and management, minor role in species listing.

• GEAC: Genetic Engineering Approval Committee, oversees biotech applications, not endangered species.

• Red List: A comprehensive inventory of the global conservation status of species.

• Conservation: Protection and management of biodiversity to prevent extinction.

• Threatened Species: Species likely to become endangered in the near future.

Lead Question – 2024

List of endangered species was released by:

(1) WWF
(2) FOAM
(3) IUCN
(4) GEAC

Explanation: The International Union for Conservation of Nature (IUCN) publishes the Red List of threatened species, which categorizes species as endangered, vulnerable, or critically endangered based on population trends, habitat, and threats. WWF supports conservation efforts but does not officially release the Red List. FOAM and GEAC do not publish global species status. This list is crucial for global biodiversity conservation, providing data for policy-making and protection measures to prevent extinction. The correct answer is IUCN. (Answer: 3)

1. Single Correct Answer:
Which organization provides international guidelines for species conservation?
(1) WWF
(2) IUCN
(3) FOAM
(4) GEAC

Explanation: The IUCN provides international standards and guidelines for conservation, including Red List assessments and management recommendations. WWF is an NGO supporting conservation projects, FOAM is a minor forum, and GEAC regulates genetic engineering. Understanding these roles is critical for biodiversity management and policy. (Answer: 2)

2. Single Correct Answer:
Which of the following categories is used in the IUCN Red List?
(1) Endangered
(2) Common
(3) Domestic
(4) Exotic

Explanation: IUCN Red List classifies species as endangered, vulnerable, or critically endangered, based on population and threat levels. Categories like common, domestic, or exotic are not part of conservation assessment. Correct classification is essential for prioritizing conservation efforts and allocating resources. (Answer: 1)

3. Single Correct Answer:
WWF primarily functions as:
(1) Global species listing authority
(2) Conservation NGO
(3) Regulatory body for genetic engineering
(4) Academic research forum

Explanation: WWF is an international NGO promoting wildlife conservation and environmental protection. It implements projects and advocacy but does not officially release the Red List. GEAC regulates biotech, FOAM is a forum, and IUCN lists species. Understanding roles of organizations helps in strategic conservation planning. (Answer: 2)

4. Single Correct Answer:
Which Indian organization oversees biotech applications but not endangered species lists?
(1) IUCN
(2) WWF
(3) GEAC
(4) FOAM

Explanation: The Genetic Engineering Approval Committee (GEAC) regulates genetically modified organisms and biotechnology applications in India. It does not release endangered species lists. IUCN handles global Red List, WWF is an NGO, and FOAM is a minor forum. Understanding these distinctions ensures correct source identification for biodiversity data. (Answer: 3)

5. Single Correct Answer:
Which list helps in prioritizing species for protection?
(1) Red List
(2) Green List
(3) Blue List
(4) Yellow List

Explanation: The IUCN Red List identifies species at risk of extinction, categorizing them as vulnerable, endangered, or critically endangered. This helps governments and organizations prioritize protection efforts, habitat conservation, and policy measures. Other colored lists are not recognized internationally for species protection purposes. (Answer: 1)

6. Single Correct Answer:
Which of the following is NOT a role of IUCN?
(1) Maintaining Red List
(2) Providing conservation guidelines
(3) Conducting ecological assessments
(4) Regulating GM crops

Explanation: IUCN focuses on species assessment, Red List maintenance, and providing conservation guidelines. It does not regulate GM crops; this is the responsibility of GEAC in India. Understanding the correct role of organizations is vital for effective biodiversity management. (Answer: 4)

7. Assertion-Reason:
Assertion (A): Endangered species require immediate conservation attention.
Reason (R): IUCN Red List classifies species based on extinction risk.
(1) Both A and R are true, R explains A
(2) Both A and R are true, R does not explain A
(3) A true, R false
(4) A false, R true

Explanation: Endangered species are at high risk of extinction, requiring immediate conservation. The IUCN Red List categorizes species based on population decline, threats, and risk of extinction. Both assertion and reason are correct, and the reason explains the need for conservation measures. (Answer: 1)

8. Matching Type:
Match the organization with its role:
A. IUCN – (i) Red List
B. WWF – (ii) Conservation NGO
C. GEAC – (iii) Biotech regulation
D. FOAM – (iv) Forum
Options:
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-i, C-iv, D-iii
(3) A-iii, B-iv, C-i, D-ii
(4) A-iv, B-iii, C-ii, D-i

Explanation: Correct pairings: IUCN manages Red List, WWF is a conservation NGO, GEAC regulates biotechnology, and FOAM is a forum for awareness. These align with the organizational roles in biodiversity protection, policy, and research. (Answer: 1)

9. Fill in the Blanks:
The ___ publishes the Red List, while ___ implements conservation projects globally.
(1) IUCN, WWF
(2) WWF, IUCN
(3) GEAC, FOAM
(4) FOAM, GEAC

Explanation: IUCN publishes the Red List assessing species' extinction risk, while WWF implements global conservation initiatives. GEAC regulates GMOs, and FOAM is a forum. Understanding functional differences ensures clarity in conservation planning. (Answer: 1)

10. Choose Correct Statements:
Statement I: IUCN releases the global Red List.
Statement II: WWF releases the official Red List.
Options:
(1) Both statements are true
(2) Statement I true, Statement II false
(3) Statement I false, Statement II true
(4) Both statements are false

Explanation: IUCN is responsible for the official Red List of threatened species. WWF supports conservation but does not release the Red List. Correct identification of authoritative sources is essential for biodiversity management and policy development. (Answer: 2)

Topic: Conservation of Biodiversity; Subtopic: Ex-situ and In-situ Conservation

Keyword Definitions:

• Biodiversity conservation: The practice of protecting and managing biological diversity of species, habitats, and ecosystems.

• Ex-situ conservation: Conservation strategy where species are protected outside their natural habitat, e.g., zoos, botanical gardens.

• In-situ conservation: Protecting species in their natural habitat without removing them from the environment.

• Semi-conservative method: Refers to DNA replication where each daughter DNA molecule contains one original and one new strand.

• Sustainable development: Development that meets present needs without compromising future generations' ability to meet their needs.

Lead Question – 2024

The type of conservation in which the threatened species are taken out from their natural habitat and placed in special setting where they can be protected and given special care is called:

(1) Biodiversity conservation
(2) Semi-conservative method
(3) Sustainable development
(4) in-situ conservation

Explanation: Ex-situ conservation involves removing threatened species from their natural habitat and protecting them in controlled settings such as zoological parks, botanical gardens, or seed banks. This method provides special care, breeding, and protection against environmental threats. In-situ conservation, by contrast, protects species in their natural habitat. The other options, biodiversity conservation, semi-conservative method, and sustainable development, do not describe this protective strategy. (Answer: 4)

1. Which of the following is an example of ex-situ conservation?
(1) National parks
(2) Wildlife sanctuaries
(3) Zoological parks
(4) Biosphere reserves

Explanation: Zoological parks represent ex-situ conservation where animals are maintained outside their natural habitat under controlled conditions for protection and breeding. National parks, wildlife sanctuaries, and biosphere reserves focus on in-situ conservation, protecting species within their natural environment. Ex-situ conservation is essential for critically endangered species needing immediate protection and recovery. (Answer: 3)

2. Which of the following is a key advantage of ex-situ conservation?
(1) Preserves entire ecosystem
(2) Protects species from immediate threats
(3) Maintains natural ecological interactions
(4) Allows unrestricted human activity

Explanation: Ex-situ conservation protects species from immediate threats such as habitat loss, hunting, or natural disasters by placing them in controlled environments. While it does not preserve the entire ecosystem or maintain natural ecological interactions, it allows focused care, breeding programs, and recovery of endangered species, ensuring their survival. (Answer: 2)

3. Seed banks are primarily associated with:
(1) In-situ conservation
(2) Ex-situ conservation
(3) Semi-conservative method
(4) Sustainable development

Explanation: Seed banks store seeds of threatened plant species under controlled conditions to maintain viability and genetic diversity. This is a form of ex-situ conservation because the seeds are preserved outside their natural habitat. In-situ conservation focuses on natural ecosystems, whereas seed banks provide long-term protection and potential restoration. (Answer: 2)

4. Which of the following is NOT an ex-situ conservation method?
(1) Botanical gardens
(2) Zoos
(3) National parks
(4) Seed banks

Explanation: National parks protect species within their natural habitats and represent in-situ conservation. Ex-situ methods involve controlled environments like zoos, botanical gardens, and seed banks, where species are maintained outside the wild. This distinction is crucial in biodiversity management. (Answer: 3)

5. Which is the primary goal of in-situ conservation?
(1) Protecting species in their natural habitats
(2) Maintaining species in controlled environments
(3) Cloning endangered species
(4) Exchanging genetic material between zoos

Explanation: In-situ conservation aims to protect species in their natural habitats, maintaining ecological interactions and evolutionary processes. It includes national parks, wildlife sanctuaries, and biosphere reserves. Ex-situ conservation, cloning, or genetic exchange are separate techniques outside natural ecosystems. (Answer: 1)

6. Which of the following is an example of a botanical garden used for ex-situ conservation?
(1) Sunderbans
(2) Lalbagh Botanical Garden
(3) Kaziranga National Park
(4) Jim Corbett National Park

Explanation: Lalbagh Botanical Garden maintains plant species outside their natural habitat, offering controlled conditions for protection and research, exemplifying ex-situ conservation. Sunderbans, Kaziranga, and Jim Corbett are natural protected areas for in-situ conservation. Botanical gardens play an important role in education, research, and preservation of rare plants. (Answer: 2)

7. Assertion-Reason Type:
Assertion (A): Ex-situ conservation is essential for critically endangered species.
Reason (R): It provides controlled environments for breeding and protection outside natural habitats.
(1) Both A and R are true and R is correct explanation of A
(2) Both A and R are true but R is not correct explanation of A
(3) A is true, R is false
(4) A is false, R is true

Explanation: Ex-situ conservation provides controlled settings for breeding, protection, and recovery of critically endangered species removed from their natural habitats. This strategy ensures survival when in-situ conservation is insufficient due to habitat destruction or extreme threats. Therefore, both Assertion and Reason are true, and Reason correctly explains Assertion. (Answer: 1)

8. Matching Type Question:
Match the conservation strategy with example:
A. In-situ – (i) Seed bank
B. Ex-situ – (ii) Biosphere reserve
C. Ex-situ – (iii) Zoological park
D. In-situ – (iv) Wildlife sanctuary
Options:
(1) A–ii, B–i, C–iii, D–iv
(2) A–iii, B–ii, C–iv, D–i
(3) A–iv, B–iii, C–i, D–ii
(4) A–i, B–iv, C–ii, D–iii

Explanation: In-situ conservation examples include biosphere reserves and wildlife sanctuaries, protecting species within natural habitats. Ex-situ conservation includes seed banks and zoological parks where species are maintained outside natural environments. Correct matching is A–ii, B–i, C–iii, D–iv. (Answer: 1)

9. Fill in the Blanks:
The conservation method where species are protected in controlled settings outside their natural habitat is called __________.
(1) In-situ conservation
(2) Ex-situ conservation
(3) Biodiversity conservation
(4) Sustainable development

Explanation: Ex-situ conservation protects species outside their natural habitats in controlled settings such as botanical gardens, zoos, and seed banks. This allows management of breeding, protection from threats, and restoration programs. In-situ conservation, by contrast, protects species in their natural environment. (Answer: 2)

10. Choose the Correct Statements:
Statement I: Ex-situ conservation is useful when in-situ conservation is not sufficient.
Statement II: Seed banks and zoological parks are examples of ex-situ conservation.
(1) Both statements are true
(2) Both statements are false
(3) Statement I is true, Statement II is false
(4) Statement I is false, Statement II is true

Explanation: Ex-situ conservation supports survival of species when natural habitats are threatened or insufficient for recovery. Seed banks and zoological parks are classic examples where species are maintained under controlled conditions for protection, breeding, and research. Both statements are correct. (Answer: 1)

Subtopic: Species Richness in Tropical Regions; Keyword Definitions:

• Tropical regions: Areas of the Earth between the Tropic of Cancer and Tropic of Capricorn, characterized by warm climate year-round.

• Species richness: Number of different species present in a defined area or ecosystem.

• Diversification: Evolutionary process by which species become varied over time.

• Niche specialization: Adaptation of species to specific environmental conditions or roles.

• Solar energy: Energy received from sunlight, influencing primary productivity and biodiversity.

• Predictable environment: Environmental conditions that remain relatively constant and stable over time.

• Seasonality: Variations in climate factors like temperature and rainfall over the year.

• Biodiversity: Variety of life forms including species diversity, genetic diversity, and ecosystem diversity.

• Ecology: Scientific study of interactions between organisms and their environment.

• Tropics: Warm climate zones that support high primary productivity and diverse habitats.

• Species diversification: Process by which species evolve to occupy different ecological niches.

Lead Question - 2024:

Tropical regions show greatest level of species richness because:
A. Tropical latitudes have remained relatively undisturbed for millions of years, hence more time was available for species diversification.
B. Tropical environments are more seasonal.
C. More solar energy is available in tropics.
D. Constant environments promote niche specialization.
E. Tropical environments are constant and predictable.
Choose the correct answer from the options given below:
(1) A and B only
(2) A, B and F only
(3) A, B and D only
(4) A, C, D and E only

Explanation: Correct answer is (4) A, C, D and E only. Tropical regions maintain high species richness because they have remained undisturbed for millions of years, allowing more time for species diversification. The high solar energy in tropics increases primary productivity. Constant, predictable environments promote niche specialization, allowing species to adapt to narrow ecological roles. Seasonal variation (option B) is lower in tropics, so it is not a major factor. The combination of historical stability, energy availability, environmental constancy, and niche specialization explains why tropical ecosystems host the greatest number of species globally.

Guessed MCQs:

1. Single Correct Answer MCQ: Which factor contributes most to species richness in tropical rainforests?
(A) High seasonality
(B) Constant and predictable climate
(C) Low solar radiation
(D) Frequent disturbances
Explanation: Correct answer is (B). Tropical rainforests are highly diverse because constant and predictable climatic conditions allow specialization and coexistence of many species over time, leading to elevated species richness compared to variable temperate regions.

2. Single Correct Answer MCQ: Which is a primary reason for species diversification in tropics?
(A) Seasonal rainfall
(B) Long-term environmental stability
(C) Frequent glaciation
(D) Extreme cold
Explanation: Correct answer is (B). Long-term environmental stability in tropical regions allows species to evolve, adapt, and diversify without major disruptions, leading to greater species richness over millions of years.

3. Single Correct Answer MCQ: High solar energy in tropical regions affects biodiversity by:
(A) Reducing primary productivity
(B) Increasing primary productivity
(C) Limiting niche specialization
(D) Decreasing species interactions
Explanation: Correct answer is (B). High solar energy boosts photosynthesis and primary productivity, providing more energy for food webs and supporting higher species richness and complex ecological interactions.

4. Single Correct Answer MCQ: Which environmental characteristic promotes niche specialization in tropics?
(A) Highly seasonal climate
(B) Constant and predictable environment
(C) Frequent disturbances
(D) Low energy input
Explanation: Correct answer is (B). Stable and predictable conditions in tropical regions allow species to specialize in narrow ecological roles, minimizing competition and supporting high species diversity.

5. Single Correct Answer MCQ: Which factor is least responsible for tropical species richness?
(A) Long evolutionary history
(B) High solar energy
(C) Frequent disturbances
(D) Constant climate
Explanation: Correct answer is (C). Frequent disturbances reduce biodiversity by periodically eliminating species, unlike the stable, resource-rich tropical environments that encourage species richness.

6. Single Correct Answer MCQ: Why are tropical regions considered hotspots of biodiversity?
(A) Low solar radiation
(B) Seasonal environments
(C) Constant, productive, and specialized niches
(D) Frequent glaciations
Explanation: Correct answer is (C). Hotspots of biodiversity are regions with high species richness due to constant climate, high productivity, and niche specialization, typical of tropical ecosystems.

7. Assertion-Reason MCQ:
Assertion (A): Tropics have the highest species richness.
Reason (R): Tropical environments are constant and predictable, promoting niche specialization.
(A) Both A and R are true and R explains A
(B) Both A and R are true but R does not explain A
(C) A is true, R is false
(D) A is false, R is true
Explanation: Correct answer is (A). The constancy and predictability of tropical environments promote niche specialization, allowing coexistence of many species, directly explaining high species richness in these regions.

8. Matching Type MCQ: Match the factor with its effect on tropical biodiversity:
List-I: (A) Solar energy (B) Environmental stability (C) Niche specialization (D) Disturbances
List-II: (I) Promotes species diversity
(II) Reduces biodiversity
(III) Supports species coexistence
(IV) Increases primary productivity
Options: (A) (B) (C) (D)
1. IV III I II
2. III IV I II
3. IV I III II
4. I II III IV
Explanation: Correct answer is 1. Solar energy increases productivity (IV), environmental stability supports coexistence (III), niche specialization promotes diversity (I), and disturbances reduce biodiversity (II).

9. Fill in the Blanks / Completion MCQ: Tropical regions maintain high species richness primarily due to _______ and predictable environments.
(A) Disturbances
(B) Constant climate
(C) Low energy
(D) Seasonal variations
Explanation: Correct answer is (B). Constant and predictable environments in tropics allow species to adapt, specialize, and coexist, leading to high species richness.

10. Choose the correct statements MCQ:
Statement I: Tropical regions have remained undisturbed for millions of years.
Statement II: High solar energy and stable environment increase species richness.
Options:
(A) Both I and II are correct
(B) Only I is correct
(C) Only II is correct
(D) Both are incorrect
Explanation: Correct answer is (A). Both historical stability and high energy availability in tropical regions promote species diversification, niche specialization, and elevated species richness, making tropics biodiversity hotspots.

Subtopic: Causes of Biodiversity Loss

Keyword Definitions:

• Biodiversity: Variety of life forms within a given ecosystem, biome, or the entire Earth, including species, genetic, and ecosystem diversity.

• Over exploitation: Unsustainable use of natural resources or species leading to population decline and possible extinction.

• Co–extinction: Extinction of a species that directly causes the extinction of dependent species.

• Mutation: Permanent alteration in the DNA sequence of an organism; usually not a major cause of biodiversity loss.

• Habitat loss and fragmentation: Destruction or division of natural habitats, reducing populations and species diversity.

• Migration: Seasonal or periodic movement of organisms; generally does not cause biodiversity loss.

• Conservation: Protection and management of ecosystems and species to maintain biodiversity.

• Extinction: Complete disappearance of a species from Earth.

• Anthropogenic impact: Human activities like deforestation, hunting, pollution causing biodiversity decline.

• Species richness: The number of different species in an ecosystem.

• Ecosystem services: Benefits humans obtain from ecosystems, such as food, water purification, and climate regulation.

Lead Question - 2024:

These are regarded as major causes of biodiversity loss:
A. Over exploitation
B. Co–extinction
C. Mutation
D. Habitat loss and fragmentation
E. Migration
Choose the correct option:
(1) A, B, C and D only
(2) A, B and E only
(3) A, B and D only
(4) A, C and D only

Explanation: Correct answer is (3) A, B and D only. Major biodiversity loss arises from over exploitation of species for food, trade, or medicine, co–extinction where dependent species disappear with the extinction of another species, and habitat loss or fragmentation that reduces species populations and connectivity. Mutation is a natural genetic process and typically does not cause mass species extinction. Migration is a normal seasonal or environmental movement and does not directly reduce biodiversity. Thus, anthropogenic and ecological factors A, B, and D are the principal contributors, and conservation efforts focus on mitigating these threats to preserve ecosystem balance and species diversity.

Guessed MCQs:

1. Single Correct Answer MCQ: Which of the following is a direct anthropogenic cause of biodiversity loss?
(A) Mutation
(B) Over exploitation
(C) Migration
(D) Natural selection
Explanation: Correct answer is (B). Over exploitation involves human activities like hunting, fishing, and logging, leading to species decline. Mutation and natural selection are natural processes, and migration does not reduce species diversity directly.

2. Single Correct Answer MCQ: Co–extinction occurs when:
(A) Two unrelated species vanish independently
(B) A species goes extinct causing dependent species to vanish
(C) Mutation accumulates over generations
(D) Migration leads to habitat overcrowding
Explanation: Correct answer is (B). Co–extinction is the secondary extinction of species that depend on a primary species. It is not due to unrelated species vanishing, mutation, or migration effects.

3. Single Correct Answer MCQ: Habitat fragmentation leads to:
(A) Increased species richness
(B) Reduced population size and connectivity
(C) Enhanced migration
(D) Genetic mutations
Explanation: Correct answer is (B). Fragmentation divides habitats into smaller, isolated patches, reducing population size, genetic diversity, and connectivity. It does not increase species richness or directly cause mutations.

4. Single Correct Answer MCQ: Which of the following does not directly cause biodiversity loss?
(A) Habitat destruction
(B) Mutation
(C) Over hunting
(D) Deforestation
Explanation: Correct answer is (B). Mutation is a natural genetic process and generally does not lead to species extinction, unlike anthropogenic factors such as hunting, deforestation, or habitat destruction.

5. Single Correct Answer MCQ: Human-induced factors affecting biodiversity are called:
(A) Natural selection
(B) Anthropogenic impacts
(C) Mutation pressures
(D) Seasonal migrations
Explanation: Correct answer is (B). Anthropogenic impacts include human activities like deforestation, pollution, and overexploitation that lead to biodiversity loss, unlike natural processes such as selection or migration.

6. Single Correct Answer MCQ: Which of the following is a major driver of co–extinction?
(A) Habitat loss
(B) Genetic mutation
(C) Seasonal migration
(D) Photosynthesis
Explanation: Correct answer is (A). Habitat loss reduces populations of key species, which can result in co–extinction of dependent species. Mutation and migration are natural processes, and photosynthesis does not affect extinction.

7. Assertion-Reason MCQ:
Assertion (A): Over exploitation is a significant cause of biodiversity loss.
Reason (R): Human activities such as hunting, logging, and fishing reduce population sizes.
(A) Both A and R are true and R explains A
(B) Both A and R are true but R does not explain A
(C) A is true, R is false
(D) A is false, R is true
Explanation: Correct answer is (A). Over exploitation directly reduces species populations through human activities, leading to biodiversity loss. R correctly explains the mechanism behind A.

8. Matching Type MCQ: Match the cause of biodiversity loss with its type:
List-I: (A) Over exploitation (B) Co–extinction (C) Mutation (D) Habitat loss
List-II: (I) Genetic process (II) Human-induced (III) Dependent species loss (IV) Environmental change
Options: (A) (B) (C) (D)
1. II III I IV
2. II IV I III
3. III II IV I
4. I II III IV
Explanation: Correct answer is 1. Over exploitation is human-induced, co–extinction involves dependent species, mutation is a genetic process, and habitat loss results from environmental or anthropogenic changes affecting species survival.

9. Fill in the Blanks / Completion MCQ: ______ and ______ are major anthropogenic causes of biodiversity loss.
(A) Mutation, Migration
(B) Over exploitation, Habitat loss
(C) Co–extinction, Mutation
(D) Migration, Mutation
Explanation: Correct answer is (B). Over exploitation and habitat loss are primary human-induced causes of biodiversity decline. Mutation and migration are natural processes and generally do not cause significant species extinction.

10. Choose the correct statements MCQ:
Statement I: Migration generally does not reduce biodiversity.
Statement II: Habitat loss and fragmentation reduce species populations and connectivity.
(A) Only Statement I is correct
(B) Only Statement II is correct
(C) Both I and II are correct
(D) Neither I nor II is correct
Explanation: Correct answer is (C). Migration is a normal seasonal movement and does not directly cause biodiversity loss. Habitat loss and fragmentation decrease population sizes, genetic diversity, and connectivity, leading to significant biodiversity decline.

Subtopic: Causes of Biodiversity Loss

Keyword Definitions:

• Biodiversity: Variety of all life forms on Earth, including genes, species, and ecosystems.

• Habitat Loss: Destruction or alteration of the natural environment where species live.

• Fragmentation: Division of large habitats into smaller, isolated patches.

• Over-exploitation: Unsustainable use of biological resources like forests, fish, and wildlife.

• Climate Change: Long-term alteration in temperature and weather patterns mainly due to human activities.

Lead Question - 2023 (Manipur)

Which of the following is/are cause(s) of biodiversity losses?

1. Over-exploitation, habitat loss and fragmentation

2. Climate change only

3. Over-exploitation only

4. Habitat loss and fragmentation only

Explanation:

The major causes of biodiversity loss include over-exploitation, habitat loss, fragmentation, pollution, invasive species, and climate change. Human activities such as deforestation, mining, and industrialization have drastically reduced species richness. Habitat destruction is the primary driver of extinction, while overuse of natural resources adds pressure. Thus, option 1 is correct.

1. Which of the following is a major cause of species extinction?

1. Natural selection

2. Habitat destruction

3. Speciation

4. Genetic drift

Explanation:

Habitat destruction leads to loss of shelter, food, and breeding grounds, directly causing species extinction. Activities like deforestation, agriculture, and urbanization remove natural habitats essential for survival. Therefore, habitat destruction is the primary anthropogenic cause of species extinction. Hence, option 2 is correct.

2. Exotic species invasion causes biodiversity loss because they:

1. Enhance native populations

2. Compete with and displace native species

3. Improve ecosystem productivity

4. Decrease environmental resistance

Explanation:

Exotic or invasive species disturb ecosystems by outcompeting native species for food, habitat, and resources. They often lack natural predators, which allows uncontrolled spread, leading to native species decline or extinction. Thus, they reduce biodiversity. Hence, option 2 is correct.

3. Which of the following is not a cause of biodiversity loss?

1. Climate change

2. Sustainable use of resources

3. Overgrazing

4. Habitat fragmentation

Explanation:

Sustainable resource use aims to balance human needs and ecosystem health without depletion. It prevents overexploitation and supports conservation. In contrast, overgrazing, climate change, and fragmentation harm biodiversity. Thus, sustainable use of resources is not a cause of biodiversity loss. Hence, option 2 is correct.

4. Deforestation affects biodiversity by:

1. Increasing habitat area

2. Reducing species diversity

3. Promoting gene flow

4. Creating new niches

Explanation:

Deforestation destroys forests, removing habitats for numerous species, reducing genetic variability, and altering food chains. Loss of vegetation also affects soil and climate balance. These factors together decrease biodiversity. Hence, option 2 is correct.

5. Which activity contributes most to marine biodiversity loss?

1. Overfishing

2. Rainwater harvesting

3. Coral reef protection

4. Artificial breeding

Explanation:

Overfishing disrupts marine ecosystems by removing key species and altering food webs. It causes population decline, threatening both predator and prey species. Sustainable fishing practices help prevent biodiversity loss. Therefore, overfishing is the major cause. Hence, option 1 is correct.

6. Which region shows the highest species loss due to human activities?

1. Temperate forests

2. Deserts

3. Tropical rainforests

4. Polar regions

Explanation:

Tropical rainforests, being biodiversity hotspots, face intense human exploitation through logging, agriculture, and mining. Their species-rich ecosystems are severely fragmented, leading to rapid extinction rates. Hence, tropical rainforests experience maximum species loss. Option 3 is correct.

7. Assertion-Reason Type:

Assertion (A): Habitat fragmentation increases edge effects.

Reason (R): Edges provide more stable conditions for interior species.

1. Both A and R are true and R is the correct explanation of A

2. Both A and R are true but R is not the correct explanation of A

3. A is true but R is false

4. Both A and R are false

Explanation:

Habitat fragmentation increases edges where environmental conditions differ from the habitat core. These edge effects expose interior species to predators and climate variation, reducing survival. The reason given is incorrect since edges are not stable for interior species. Hence, option 3 is correct.

8. Matching Type:

Match the causes with their examples.

A. Overexploitation — (i) Hunting of tigers

B. Habitat loss — (ii) Deforestation

C. Invasive species — (iii) Water hyacinth

D. Pollution — (iv) Eutrophication

1. A-(i), B-(ii), C-(iii), D-(iv)

2. A-(ii), B-(i), C-(iv), D-(iii)

3. A-(iv), B-(iii), C-(i), D-(ii)

4. A-(i), B-(iii), C-(ii), D-(iv)

Explanation:

Overexploitation involves excessive hunting or harvesting (A-i), habitat loss results from deforestation (B-ii), invasive species like water hyacinth harm aquatic ecosystems (C-iii), and pollution causes eutrophication (D-iv). These are direct threats to biodiversity. Hence, option 1 is correct.

9. Fill in the Blanks:

___________ and ___________ are the two major causes of biodiversity loss worldwide.

1. Deforestation and Overexploitation

2. Migration and Mutation

3. Evolution and Adaptation

4. Domestication and Selection

Explanation:

Deforestation eliminates habitats, while overexploitation depletes natural populations. Together, they are the most significant global causes of biodiversity decline. Conservation programs focus on reducing these practices to maintain ecological balance. Hence, option 1 is correct.

10. Choose the Correct Statements:

Statement I: Habitat destruction leads to species extinction.

Statement II: Pollution enhances biodiversity.

1. Both statements are true

2. Statement I is true and Statement II is false

3. Both statements are false

4. Statement I is false and Statement II is true

Explanation:

Habitat destruction is indeed the leading cause of species extinction, while pollution degrades habitats, harming organisms and reducing biodiversity. Thus, the first statement is correct and the second is false. Hence, option 2 is correct. 

Topic: Biodiversity Concepts

Subtopic: Rivet Popper Hypothesis & Genetic Diversity

• Rivet Popper Hypothesis: A hypothesis by Paul Ehrlich likening species in ecosystems to rivets in an airplane, emphasizing species loss consequences.

• Species: A group of organisms capable of interbreeding and producing fertile offspring.

• Genetic Diversity: Variation of genes within a species that ensures adaptability and survival.

• Genus: Taxonomic rank above species, grouping similar species together.

• Family: Taxonomic rank above genus, grouping related genera.

• Ecosystem: A community of living organisms interacting with each other and their physical environment.

• Extinction: Complete disappearance of a species from the Earth.

• Biodiversity: Variety and variability of life forms within a given ecosystem, biome, or the entire Earth.

• Paul Ehrlich: Scientist and ecologist who proposed the rivet popper hypothesis.

• Conservation: Protection, preservation, management, or restoration of natural environments and their inhabitants.

• Species Loss: The decline or extinction of species, leading to weakened ecosystem stability.

Lead Question - 2023 (Manipur)

In 'rivet popper hypothesis', Paul Ehrlich compared the rivets in an airplane to:

• 1. species within a genus

• 2. genetic diversity

• 3. ecosystem

• 4. genera within a family

Explanation: In the rivet popper hypothesis, each species in an ecosystem is compared to a rivet in an airplane; removing rivets (species) weakens the structure and can cause collapse. Paul Ehrlich emphasized the importance of individual species for ecosystem stability. Thus, rivets correspond to species within a genus. Correct answer: 1. This illustrates how species loss reduces ecosystem resilience and highlights the role of biodiversity.

1. Which type of biodiversity refers to variety of genes within a species?

• a) Species diversity

• b) Genetic diversity

• c) Ecosystem diversity

• d) Functional diversity

Explanation: Genetic diversity is the variation in genetic makeup among individuals within a species. It allows adaptation to environmental changes, prevents inbreeding depression, and ensures long-term survival. Species diversity refers to number of species, ecosystem diversity to variety of ecosystems, and functional diversity to ecological roles. Correct answer: b.

2. The loss of a keystone species primarily affects:

• a) Genetic diversity only

• b) Ecosystem structure and stability

• c) Taxonomic classification

• d) Family relationships

Explanation: Keystone species play crucial roles in maintaining ecosystem structure and stability. Their loss disrupts ecological interactions, leading to cascading effects. Genetic diversity may be affected indirectly. Taxonomic classification and family relationships are not directly impacted. Correct answer: b.

3. Biodiversity hotspots are regions with:

• a) Low species richness

• b) High species richness and endemism

• c) Mostly introduced species

• d) Uniform ecosystems

Explanation: Biodiversity hotspots are regions with high species richness, especially of endemic species, and are under significant threat. They are crucial for conservation priority. Low species richness, introduced species dominance, or uniform ecosystems do not qualify as biodiversity hotspots. Correct answer: b.

4. In an ecosystem, the total number of species is referred to as:

• a) Species richness

• b) Species evenness

• c) Functional diversity

• d) Genetic diversity

Explanation: Species richness denotes the total number of species present in an ecosystem, while species evenness reflects abundance distribution among species. Functional diversity pertains to roles species play, and genetic diversity is variation within species. Therefore, species richness measures overall species count. Correct answer: a.

5. The main aim of conservation biology is to:

• a) Classify species

• b) Protect species, habitats, and ecosystems

• c) Promote monocultures

• d) Increase human population

Explanation: Conservation biology focuses on protecting species, habitats, and ecosystems to maintain biodiversity, ecosystem services, and genetic resources. Classification, monoculture promotion, and human population growth are unrelated to conservation objectives. Correct answer: b.

6. Which of the following is an example of in situ conservation?

• a) Botanical gardens

• b) Wildlife sanctuaries

• c) Seed banks

• d) Zoos

Explanation: In situ conservation involves protecting species within their natural habitats, such as wildlife sanctuaries and national parks. Botanical gardens, seed banks, and zoos are ex situ conservation strategies where species are maintained outside their natural environment. Correct answer: b.

7. Assertion (A): Loss of species affects ecosystem stability.
Reason (R): Each species contributes to ecosystem functions like nutrient cycling and pollination.

• a) Both A and R are true, and R is the correct explanation of A

• b) Both A and R are true, but R is not the correct explanation of A

• c) A is true, R is false

• d) A is false, R is true

Explanation: Species loss disrupts ecosystem functions such as nutrient cycling, food web interactions, and pollination. Each species contributes uniquely to ecosystem stability. Therefore, both assertion and reason are correct, with reason accurately explaining the assertion. Correct answer: a.

8. Match the following:

• Column I: 1. In situ conservation 2. Ex situ conservation 3. Biodiversity hotspot

• Column II: a. Seed banks and zoos b. Western Ghats c. National parks and sanctuaries

Choices:
a) 1-c, 2-a, 3-b
b) 1-a, 2-c, 3-b
c) 1-b, 2-c, 3-a
d) 1-c, 2-b, 3-a

Explanation: In situ conservation protects species in their natural habitats like national parks, ex situ conservation uses seed banks or zoos, and biodiversity hotspots like Western Ghats are regions with high species richness and endemism. Correct matching: 1-c, 2-a, 3-b. Correct answer: a.

9. Fill in the blank: ___________ is the total variety of species, genes, and ecosystems in a region or on Earth.

• a) Genetic diversity

• b) Biodiversity

• c) Ecosystem diversity

• d) Functional diversity

Explanation: Biodiversity encompasses the variety of life at all levels, including genetic variation within species, number of species, and diversity of ecosystems. It ensures ecosystem resilience, supports ecosystem services, and maintains evolutionary processes. Correct answer: b.

10. Choose the correct statements:

Statement I: Endangered species require urgent conservation action.
Statement II: Biodiversity loss can weaken ecosystem stability and services.

• a) Both Statement I and Statement II are correct

• b) Statement I is correct, Statement II is incorrect

• c) Statement I is incorrect, Statement II is correct

• d) Both Statement I and Statement II are incorrect

Explanation: Endangered species are at risk of extinction and need protection. Loss of species diminishes ecosystem functions, reduces resilience, and disrupts services like pollination and nutrient cycling. Both statements accurately reflect conservation principles and ecosystem dynamics. Correct answer: a.

Topic: Biodiversity Conservation; Subtopic: Convention on Biological Diversity

Keyword Definitions:

• Convention on Biological Diversity (CBD): International treaty for conservation, sustainable use, and equitable sharing of biodiversity resources.

• Earth Summit: United Nations Conference on Environment and Development held to address global environmental issues.

• Rio de Janeiro: City in Brazil where the 1992 Earth Summit was held.

• Biodiversity: Variety of life forms, including genes, species, and ecosystems.

• Sustainable Use: Using biodiversity resources without depleting them for future generations.

• Equitable Sharing: Fair distribution of benefits arising from the use of biological resources.

• Global Treaty: International agreement among countries to achieve common environmental goals.

• Agenda 21: Action plan for sustainable development adopted at the Earth Summit.

• Bio-prospecting: Exploration of biodiversity for commercially valuable genetic and biochemical resources.

• Environmental Policy: Strategies adopted by nations for biodiversity conservation and sustainable development.

• United Nations: International organization promoting cooperation on global issues including environment.

Lead Question - 2023:

The historic Convention on Biological Diversity, ‘The Earth Summit’ was held in Rio de Janeiro in the year:
(1) 1986
(2) 2002
(3) 1985
(4) 1992

Answer & Explanation: (4) 1992. The Earth Summit, officially called the United Nations Conference on Environment and Development, took place in Rio de Janeiro in 1992. It led to the adoption of the Convention on Biological Diversity (CBD), which aims at conserving global biodiversity, promoting sustainable use of biological resources, and ensuring fair sharing of benefits arising from genetic resources. Agenda 21, a comprehensive action plan for sustainable development, was also formulated. This summit was historic as it brought together 178 countries, civil society, and indigenous groups to address pressing environmental issues and set a framework for global biodiversity governance for the 21st century.

1. The main objective of the CBD is:
(1) Reduce greenhouse gases
(2) Conserve biodiversity, sustainable use, equitable sharing
(3) Promote fossil fuel use
(4) Eliminate endangered species
Explanation: CBD aims to conserve biodiversity, use biological resources sustainably, and share benefits equitably. Correct answer is (2).

2. Rio de Janeiro Earth Summit is also called:
(1) Kyoto Protocol
(2) Stockholm Conference
(3) UNCED 1992
(4) Paris Agreement
Explanation: The 1992 Rio Earth Summit is officially the United Nations Conference on Environment and Development (UNCED). Correct answer is (3).

3. Agenda 21 is associated with:
(1) Nuclear energy
(2) Global warming only
(3) Sustainable development action plan
(4) Space exploration
Explanation: Agenda 21 is a comprehensive plan for sustainable development adopted at the 1992 Earth Summit. Correct answer is (3).

4. Number of countries that signed CBD initially:
(1) 50
(2) 178
(3) 100
(4) 200
Explanation: At the 1992 Rio Summit, 178 countries signed the Convention on Biological Diversity. Correct answer is (2).

5. CBD promotes sustainable use of:
(1) Fossil fuels
(2) Biological resources
(3) Minerals only
(4) Industrial chemicals
Explanation: CBD encourages using biodiversity and biological resources in ways that do not deplete them for future generations. Correct answer is (2).

6. Equity sharing in CBD refers to:
(1) Sharing economic profits from genetic resources
(2) Sharing climate data
(3) Sharing water equally
(4) Sharing land rights
Explanation: CBD ensures fair distribution of benefits arising from genetic resources among all stakeholders. Correct answer is (1).

Assertion-Reason Type Question
7. Assertion (A): The CBD is legally binding for signatory countries.
Reason (R): Countries must implement national strategies for biodiversity conservation.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: CBD is a legally binding treaty, and signatory countries are required to implement national biodiversity strategies and action plans. Correct answer is (1).

Matching Type Question
8. Match:
A. Rio Summit – (i) 1992, CBD adoption
B. Stockholm – (ii) 1972, first UN environmental conference
C. Kyoto – (iii) 1997, greenhouse gas reduction
D. Paris – (iv) 2015, climate agreement
(1) A-(i), B-(ii), C-(iii), D-(iv)
(2) A-(ii), B-(i), C-(iv), D-(iii)
(3) A-(iii), B-(iv), C-(i), D-(ii)
(4) A-(iv), B-(iii), C-(ii), D-(i)
Explanation: Rio Summit (1992) led to CBD adoption; Stockholm (1972) first UN environmental conference; Kyoto (1997) for emissions reduction; Paris (2015) climate agreement. Correct answer is (1).

Fill in the Blanks Question
9. The Earth Summit held in _______ led to adoption of the Convention on Biological Diversity.
(1) 1986
(2) 2002
(3) 1992
(4) 1985
Explanation: The 1992 Rio Earth Summit adopted the CBD for global biodiversity conservation. Correct answer is (3).

Choose the Correct Statements Question
10. Statement I: CBD aims to conserve biodiversity.
Statement II: CBD only applies to developed countries.
(1) I true, II false
(2) I false, II true
(3) Both true
(4) Both false
Explanation: CBD applies globally, aiming to conserve biodiversity and ensure sustainable use. Statement I true, II false. Correct answer is (1).

Chapter: Biodiversity and Conservation; Topic: Loss of Biodiversity; Subtopic: The Evil Quartet and Causes of Species Extinction

Keyword Definitions:

• Biodiversity: Variety and variability among living organisms at genetic, species, and ecosystem levels on Earth.

• Extinction: The complete disappearance of a species from Earth due to environmental or anthropogenic causes.

• Habitat Fragmentation: Breaking of large continuous habitats into smaller, isolated patches affecting species survival.

• Alien Species: Non-native organisms introduced deliberately or accidentally into new ecosystems, often becoming invasive.

• Co-extinction: When one species’ extinction leads to the loss of another species dependent on it.

• Overexploitation: Unsustainable harvesting of species for human use, leading to depletion and extinction.

Lead Question – 2023

Among ‘The Evil Quartet’ which one is considered the most important cause driving extinction of species?
(1) Alien species invasions
(2) Co-extinctions
(3) Habitat loss and fragmentation
(4) Over exploitation for economic gain

Answer & Explanation: (3) Habitat loss and fragmentation. It is the leading cause of biodiversity loss as deforestation, urbanization, and agricultural expansion destroy natural habitats. Species lose shelter, food, and breeding areas, reducing genetic diversity and leading to extinction. Fragmentation isolates populations, making them vulnerable to environmental changes and human interference.

1. Which of the following is not a component of the Evil Quartet?
(1) Overexploitation
(2) Alien species invasion
(3) Genetic drift
(4) Co-extinction
Answer & Explanation: (3) Genetic drift. The Evil Quartet comprises habitat loss, overexploitation, alien species invasion, and co-extinction. Genetic drift is a microevolutionary process altering gene frequencies, but it is not a direct anthropogenic cause of extinction like the other four factors mentioned.

2. The introduction of Nile Perch into Lake Victoria led to:
(1) Increase in native fish species
(2) Decline of cichlid species
(3) Control of aquatic weeds
(4) Improvement in biodiversity
Answer & Explanation: (2) Decline of cichlid species. The introduction of Nile Perch, an alien predatory fish, caused the extinction of hundreds of endemic cichlid species in Lake Victoria. This represents a classic case of alien species invasion causing severe ecological imbalance and biodiversity loss.

3. The extinction of a plant species leading to the disappearance of a butterfly species dependent on it is an example of:
(1) Adaptive radiation
(2) Co-extinction
(3) Speciation
(4) Endemism
Answer & Explanation: (2) Co-extinction. When a host species becomes extinct, the dependent species, such as pollinators, parasites, or symbionts, also vanish. This interdependent extinction emphasizes the fragility of ecological relationships and the importance of conserving entire ecosystems, not just individual species.

4. Dodo extinction was mainly caused by:
(1) Habitat loss and hunting
(2) Climate change
(3) Volcanic eruption
(4) Viral epidemic
Answer & Explanation: (1) Habitat loss and hunting. The Dodo, native to Mauritius, was wiped out in the 17th century due to overhunting by sailors and habitat destruction caused by introduced animals. It is a classic example of human-induced extinction through overexploitation and habitat loss.

5. The Silent Valley project in Kerala was associated with conservation of:
(1) Tropical rainforests
(2) Coral reefs
(3) Desert ecosystems
(4) Alpine meadows
Answer & Explanation: (1) Tropical rainforests. The Silent Valley project aimed to conserve one of the last tropical evergreen forests in India threatened by dam construction. Its success highlights the importance of conserving biodiversity-rich habitats to prevent loss of endemic species and ecological services.

6. Which of the following pairs is correctly matched?
(1) Alien species invasion – Biodiversity increase
(2) Overexploitation – Species decline
(3) Co-extinction – New species formation
(4) Habitat loss – Genetic uniformity
Answer & Explanation: (2) Overexploitation – Species decline. Unsustainable use of species for trade or consumption leads to population depletion and eventual extinction. Overfishing, poaching, and deforestation exemplify this, as seen in the extinction of the passenger pigeon and near-extinction of tigers and whales.

7. (Assertion–Reason Type)
Assertion (A): Co-extinction is an indirect cause of species loss.
Reason (R): It occurs when one species depends completely on another for survival.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true, but R is false.
(4) A is false, but R is true.
Answer & Explanation: (1) Both A and R are true, and R explains A. Co-extinction happens when dependent species, like pollinators or parasites, disappear following their host’s extinction. It highlights interconnectedness in ecosystems and the cascading effects of species loss on biodiversity.

8. (Matching Type)
Match the causes of extinction with their examples:
A. Habitat loss – (i) Amazon rainforest destruction
B. Alien species invasion – (ii) Nile Perch in Lake Victoria
C. Overexploitation – (iii) Dodo extinction
D. Co-extinction – (iv) Loss of pollinators with host plants
(1) A–i, B–ii, C–iii, D–iv
(2) A–ii, B–i, C–iv, D–iii
(3) A–iii, B–ii, C–i, D–iv
(4) A–iv, B–iii, C–ii, D–i
Answer & Explanation: (1) A–i, B–ii, C–iii, D–iv. Each represents a distinct mechanism in biodiversity loss, demonstrating how human activities and ecological dependencies accelerate global extinction rates and disrupt ecosystem balance.

9. (Fill in the Blanks)
__________ occurs when the destruction of large continuous forests results in isolated patches of smaller habitats.
(1) Co-extinction
(2) Habitat fragmentation
(3) Adaptive radiation
(4) Genetic drift
Answer & Explanation: (2) Habitat fragmentation. It reduces gene flow and increases vulnerability to extinction due to smaller population sizes. Fragmentation also increases edge effects, exposing interior species to predators, human interference, and changing microclimates, ultimately threatening ecosystem stability.

10. (Choose the Correct Statements Type)
Statement I: Alien species invasions always benefit native biodiversity.
Statement II: Overexploitation and habitat destruction reduce ecosystem resilience.
(1) Both statements are correct.
(2) Both statements are incorrect.
(3) Statement I is correct, II is incorrect.
(4) Statement I is incorrect, II is correct.
Answer & Explanation: (4) Statement I is incorrect, II is correct. Alien species often harm native biodiversity by outcompeting native species. Overexploitation and habitat destruction destabilize ecosystems, reducing resilience and adaptability against environmental changes and increasing extinction risks.

Chapter: Biodiversity and Conservation; Topic: Species Diversity; Subtopic: Endemism and Threatened Species

Keyword Definitions:

• Endemic species: Species found only in a specific geographical area and nowhere else.

• Threatened species: Species at risk of extinction in the near future.

• Keystone species: Species that have a disproportionately large effect on its ecosystem.

• Vulnerable species: Species facing a high risk of extinction in the medium term.

• Biodiversity: Variety of life forms in a given ecosystem or region.

• Western Ghats: Mountain range in India, rich in endemic flora and fauna.

• Conservation: Protection and preservation of biodiversity.

• Habitat specificity: Adaptation of species to a particular habitat.

• Extinction risk: Probability of a species disappearing from the planet.

• Flora and fauna: Plant and animal life of a region.

• Biogeography: Study of distribution of species across geographic regions.

Lead Question - 2022 (Ganganagar)

Western Ghats have a large number of plants and animal species that are not found anywhere else. Which of the following term is used to notify such species?

1. Threatened species

2. Keystone species

3. Endemic species

4. Vulnerable species

Explanation: Species that are found exclusively in a specific geographic area, such as the Western Ghats, are termed endemic species. These species do not naturally occur anywhere else. Threatened or vulnerable species face risks of extinction, while keystone species play critical roles in ecosystem functioning. Endemism highlights unique biodiversity and is crucial for conservation planning. Correct answer is 3.

1. Single Correct Answer MCQ:

Which of the following is a species found only in the Galápagos Islands?

a) Polar bear

b) Giant tortoise

c) Lion

d) Kangaroo

Explanation: The giant tortoise is endemic to the Galápagos Islands, meaning it is naturally found only in that region. Endemic species indicate habitat specificity and biogeographical uniqueness. Correct answer is b.

2. Single Correct Answer MCQ:

Which species affects ecosystem structure disproportionately?

a) Endemic species

b) Keystone species

c) Vulnerable species

d) Threatened species

Explanation: Keystone species influence ecosystem dynamics significantly. Their removal can cause cascading effects, unlike endemic species which are region-specific. Correct answer is b.

3. Single Correct Answer MCQ:

A species at high risk of extinction in near future is called:

a) Vulnerable

b) Endangered

c) Keystone

d) Exotic

Explanation: Endangered species face imminent risk of extinction, requiring urgent conservation measures. Correct answer is b.

4. Single Correct Answer MCQ:

Vulnerable species are those:

a) Only in captivity

b) Facing high risk of extinction in medium term

c) Found in multiple continents

d) Unaffected by habitat loss

Explanation: Vulnerable species are at a high risk of extinction over a medium-term period, often due to habitat loss or exploitation. Correct answer is b.

5. Single Correct Answer MCQ:

Which factor contributes most to species endemism?

a) Widespread distribution

b) Habitat specificity

c) High mobility

d) Low reproduction

Explanation: Habitat specificity restricts species to particular regions, leading to endemism. Western Ghats show high endemism due to unique ecological conditions. Correct answer is b.

6. Single Correct Answer MCQ:

Which of the following is not a conservation priority indicator?

a) Endemism

b) Threatened status

c) Keystone role

d) Random species

Explanation: Random species without ecological significance or conservation concern are not prioritized. Endemism, threatened status, and keystone species guide conservation planning. Correct answer is d.

7. Assertion-Reason MCQ:

Assertion (A): Western Ghats have high endemic species.

Reason (R): Endemic species are found only in specific geographic areas.

a) Both A and R true, R explains A

b) Both A and R true, R does not explain A

c) A true, R false

d) Both false

Explanation: Both statements are true; endemism explains the unique species in Western Ghats. Correct answer is a.

8. Matching Type MCQ:

Match List-I with List-II:

List-I | List-II

(a) Western Ghats | (i) Vulnerable species

(b) Amazon rainforest | (ii) Endemic species

(c) Sunderbans | (iii) Keystone species

(d) Coral reefs | (iv) Threatened species

Options:

1. a-ii, b-iii, c-iv, d-i

2. a-ii, b-iv, c-i, d-iii

3. a-i, b-ii, c-iii, d-iv

4. a-iii, b-i, c-ii, d-iv

Explanation: Western Ghats (endemic), Amazon rainforest (keystone), Sunderbans (threatened), Coral reefs (vulnerable). Correct answer is 1.

9. Fill in the Blanks / Completion MCQ:

Species found only in a defined geographical region are called ________.

a) Threatened species

b) Endemic species

c) Keystone species

d) Migratory species

Explanation: Endemic species are restricted to particular regions like Western Ghats and do not naturally occur elsewhere. Correct answer is b.

10. Choose the correct statements MCQ (Statement I & II):

Statement I: Endemic species are found only in specific regions.

Statement II: Keystone species control ecosystem structure disproportionately.

a) Both I and II correct

b) Only I correct

c) Only II correct

d) Both incorrect

Explanation: Both statements are correct; endemism defines regional uniqueness and keystone species maintain ecological balance. Correct answer is a. 

Topic: Biodiversity and Conservation Strategies; Subtopic: In-situ and Ex-situ Conservation

Keyword Definitions:

• Sacred groves: Patches of forest protected by local communities for religious or cultural reasons.

• Zoological park: Facility where animals are kept in captivity for conservation, education, and research.

• Nile perch: Large predatory fish introduced into African lakes, considered an alien or invasive species.

• Amazon forest: Vast tropical rainforest releasing large amounts of oxygen and maintaining global biodiversity.

• Alien species: Non-native organisms introduced to new ecosystems, often causing ecological imbalance.

• Ex-situ conservation: Conservation of species outside their natural habitats, e.g., in zoos or botanical gardens.

• In-situ conservation: Conservation of species in their natural habitat, such as national parks or reserves.

• Biodiversity hotspot: Region rich in endemic species and under threat from human activities.

• Khasi Hills: Area in Meghalaya, India, known for preserved sacred groves.

• Oxygen release: Process by which forests contribute to atmospheric oxygen through photosynthesis.

• Conservation strategy: Measures taken to protect species and ecosystems from extinction or degradation.

Lead Question - 2022 (Ganganagar)

Match List-I with List-II:

List-I  List-II

(a) Sacred groves (i) Alien species

(b) Zoological park (ii) Release of large quantity of oxygen

(c) Nile perch (iii) Ex-situ conservation

(d) Amazon forest (iv) Khasi Hills in Meghalaya

Choose the correct answer from the options given below:

1. (iv) (iii) (i) (ii)

2. (ii) (iv) (i) (iii)

3. (iv) (i) (ii) (iii)

4. (iv) (iii) (ii) (i)

Explanation: Sacred groves in Khasi Hills represent in-situ conservation of culturally significant forests (a-iv). Zoological parks exemplify ex-situ conservation where animals are preserved outside natural habitats (b-iii). Nile perch is an introduced species causing ecological imbalance in African lakes (c-i). Amazon forest is a vast rainforest contributing large amounts of oxygen to the atmosphere (d-ii). Correct answer is 1. (iv) (iii) (i) (ii). These classifications help in understanding conservation strategies and biodiversity management, highlighting the importance of both in-situ and ex-situ approaches in preserving species and ecological balance under human influence.

1. Single Correct Answer MCQ:

Which of the following represents in-situ conservation?

a) Zoological park

b) Sacred groves

c) Botanical garden

d) Seed bank

Explanation: In-situ conservation occurs within natural habitats. Sacred groves are preserved areas maintained by communities, protecting species in their original ecosystem. Zoological parks, botanical gardens, and seed banks represent ex-situ methods. Correct answer is b) Sacred groves.

2. Single Correct Answer MCQ:

Nile perch is an example of:

a) Native species

b) Keystone species

c) Alien species

d) Endangered species

Explanation: Nile perch was introduced into African lakes and is not native, causing ecological imbalance. It represents an alien or invasive species. Correct answer is c) Alien species.

3. Single Correct Answer MCQ:

Which entity releases large amounts of oxygen?

a) Desert ecosystems

b) Amazon forest

c) Zoological park

d) Sacred groves

Explanation: The Amazon rainforest, with dense vegetation, performs extensive photosynthesis, releasing significant oxygen and maintaining global air quality. Correct answer is b) Amazon forest.

4. Single Correct Answer MCQ:

Ex-situ conservation is demonstrated by:

a) National park

b) Sacred groves

c) Zoological park

d) Wildlife sanctuary

Explanation: Zoological parks preserve animals outside their natural habitats for protection and breeding, exemplifying ex-situ conservation. Correct answer is c) Zoological park.

5. Single Correct Answer MCQ:

Khasi Hills in Meghalaya are known for:

a) Alien species introduction

b) Sacred groves

c) Desertification

d) Mangrove conservation

Explanation: Khasi Hills are culturally rich regions preserving sacred groves for in-situ conservation. Correct answer is b) Sacred groves.

6. Single Correct Answer MCQ:

Which is NOT a method of conservation?

a) Seed bank

b) Sacred grove

c) Industrial effluent dumping

d) Zoological park

Explanation: Industrial effluent dumping harms ecosystems and does not conserve biodiversity. Seed banks, sacred groves, and zoos preserve species. Correct answer is c) Industrial effluent dumping.

7. Assertion-Reason MCQ:

Assertion (A): Amazon forest is called the “lungs of Earth”.

Reason (R): It releases large quantities of oxygen through photosynthesis.

a) Both A and R are true, R explains A

b) Both A and R are true, R does not explain A

c) A is true, R is false

d) A is false, R is true

Explanation: The Amazon rainforest performs massive photosynthesis, producing oxygen and regulating climate. Both assertion and reason are true, and the reason explains the assertion. Correct answer is a) Both A and R are true, R explains A.

8. Matching Type MCQ:

Match with correct conservation type:

Column I

A) Sacred groves

B) Zoological park

C) Amazon forest

D) Nile perch

Column II

1) In-situ conservation

2) Ex-situ conservation

3) Oxygen release

4) Alien species

Choices:

A-__ B-__ C-__ D-__

Explanation: Correct matches: A-1 (Sacred groves – in-situ), B-2 (Zoological park – ex-situ), C-3 (Amazon forest – oxygen release), D-4 (Nile perch – alien species). This categorization aids understanding of conservation and ecological impact.

9. Fill in the Blanks / Completion MCQ:

_________ preserves species in their natural habitat.

a) Zoological park

b) Sacred groves

c) Botanical garden

d) Seed bank

Explanation: Sacred groves protect plants and animals within their natural ecosystem, ensuring in-situ conservation. Correct answer is b) Sacred groves.

10. Choose the correct statements MCQ (Statement I & II):

Statement I: Zoological parks are examples of ex-situ conservation.

Statement II: Sacred groves represent in-situ conservation.

a) Both I and II are correct

b) Only I is correct

c) Only II is correct

d) Both are incorrect

Explanation: Zoological parks conserve animals outside natural habitats (ex-situ), and sacred groves preserve species in their native ecosystem (in-situ). Both statements are correct. Correct answer is a) Both I and II are correct. 

Topic: Biodiversity Conservation; Subtopic: International Efforts for Sustainable Development

Keyword Definitions:

• World Summit on Sustainable Development (WSSD): International conference held in 2002 in Johannesburg to promote sustainable development globally.

• Biodiversity: Variety of life on Earth, including species, genetic, and ecosystem diversity.

• Biodiversity loss: Decline in species, genetic variation, and ecosystem stability due to human activities.

• Biodiversity hotspots: Regions rich in endemic species but under threat.

• Sustainable development: Development meeting present needs without compromising future generations.

• Seed preservation: Collecting and storing seeds of important plant species for conservation.

• Genetic strains: Variants within species important for agriculture and resilience.

• Agricultural production: Farming outputs including crops, livestock, and related products.

• Conservation: Protection and management of biodiversity and natural resources.

• Johannesburg Summit 2002: Focused on global strategies for environmental sustainability, poverty alleviation, and conservation.

• International pledges: Commitments by countries to achieve specific environmental or development goals.

Lead Question - 2022 (Ganganagar)

The World Summit on sustainable development held in 2002 in Johannesburg, South Africa pledged for:

1. A significant reduction in the current rate of biodiversity loss.

2. Declaration of more biodiversity hotspots.

3. Increase in agricultural production

4. Collection and preservation of seeds of different genetic strains of commercially important plants.

Explanation: The 2002 Johannesburg World Summit focused on sustainable development, with one major pledge to significantly reduce the rate of biodiversity loss globally. This aimed to conserve ecosystems, species, and genetic diversity to ensure long-term environmental health. While seed preservation and agricultural improvements are important, the specific global commitment emphasized halting biodiversity decline. Declaration of new biodiversity hotspots was not a direct WSSD pledge. Thus, the correct answer is 1. A significant reduction in the current rate of biodiversity loss. This commitment reflects international efforts to balance development with environmental sustainability.

1. Single Correct Answer MCQ:

Biodiversity hotspots are identified based on:

a) Economic development

b) High species richness and endemism

c) Climatic stability

d) Political boundaries

Explanation: Biodiversity hotspots are regions with high species richness, many endemic species, and significant habitat loss. Economic development, climate, or political borders are not criteria for hotspot designation. Protecting these areas helps prevent species extinction. Correct answer is b) High species richness and endemism.

2. Single Correct Answer MCQ:

Which international conference focused on sustainable development in 2002?

a) Rio Earth Summit

b) Johannesburg World Summit

c) Kyoto Protocol Meeting

d) Stockholm Conference

Explanation: The Johannesburg World Summit on Sustainable Development in 2002 brought together nations to discuss sustainable development, poverty reduction, and biodiversity conservation. Rio Summit was in 1992, Kyoto Protocol focused on climate change, and Stockholm Conference was in 1972. Correct answer is b) Johannesburg World Summit.

3. Single Correct Answer MCQ:

A major goal of WSSD was:

a) Expansion of deserts

b) Reduction of biodiversity loss

c) Increase in fossil fuel usage

d) Urban expansion

Explanation: The summit emphasized halting biodiversity loss, promoting conservation and sustainable use of natural resources. Expanding deserts or fossil fuel use contradict sustainability, and urban growth alone is not a goal. Correct answer is b) Reduction of biodiversity loss.

4. Single Correct Answer MCQ:

Seed banks primarily help in:

a) Reducing greenhouse gases

b) Preserving genetic diversity of plants

c) Increasing industrial production

d) Expanding urban areas

Explanation: Seed banks collect and store seeds of diverse plant species to preserve genetic diversity for future use in agriculture, research, or restoration. This ensures conservation against extinction. They do not directly reduce greenhouse gases or affect urban or industrial growth. Correct answer is b) Preserving genetic diversity of plants.

5. Single Correct Answer MCQ:

Which is NOT a direct WSSD pledge regarding biodiversity?

a) Reducing biodiversity loss

b) Sustainable use of resources

c) Declaring more biodiversity hotspots

d) Conservation of endangered species

Explanation: WSSD focused on reducing biodiversity loss, sustainable resource use, and conservation, but declaring new biodiversity hotspots was not a formal pledge. Correct answer is c) Declaring more biodiversity hotspots.

6. Single Correct Answer MCQ:

Sustainable development aims to:

a) Exploit natural resources quickly

b) Meet present needs without compromising future generations

c) Halt all economic activity

d) Increase pollution for industrial growth

Explanation: Sustainable development seeks balance between present human needs and long-term environmental protection, ensuring resources remain available for future generations. Exploitation or pollution contradicts this principle. Correct answer is b) Meet present needs without compromising future generations.

7. Assertion-Reason MCQ:

Assertion (A): Biodiversity loss reduction was a key goal of WSSD.

Reason (R): Loss of biodiversity threatens ecosystem services, human health, and economic stability.

a) Both A and R are true, R explains A

b) Both A and R are true, R does not explain A

c) A is true, R is false

d) A is false, R is true

Explanation: WSSD emphasized halting biodiversity loss due to its impact on ecosystems, food security, and global well-being. The reason explains why biodiversity conservation is critical for sustainable development. Both statements are true and linked. Correct answer is a) Both A and R are true, R explains A.

8. Matching Type MCQ:

Match the term with its focus area:

Column I

A) Seed banks

B) Biodiversity hotspots

C) WSSD

D) Conservation programs

Column II

1) Preserving genetic diversity

2) Regions with high endemism

3) International sustainable development efforts

4) Protecting endangered species

Choices:

A-__ B-__ C-__ D-__

Explanation: Seed banks preserve genetic diversity (A-1), biodiversity hotspots are high endemism regions (B-2), WSSD coordinates international sustainability efforts (C-3), and conservation programs protect endangered species (D-4). Correct matches: A-1, B-2, C-3, D-4.

9. Fill in the Blanks / Completion MCQ:

The 2002 Johannesburg Summit emphasized __________ as a global environmental goal.

a) Expansion of mining

b) Reduction in biodiversity loss

c) Increased industrial production

d) Urbanization

Explanation: The WSSD focused on halting biodiversity loss to maintain ecosystem health and support sustainable development. Industrial growth, mining, or urbanization were not the central environmental goals. Correct answer is b) Reduction in biodiversity loss.

10. Choose the correct statements MCQ (Statement I & II):

Statement I: WSSD 2002 aimed to reduce the rate of biodiversity loss.

Statement II: Sustainable development ensures resources for future generations.

a) Both I and II are correct

b) Only I is correct

c) Only II is correct

d) Both are incorrect

Explanation: WSSD targeted biodiversity conservation, while sustainable development principles ensure long-term availability of resources. Both statements are accurate and interrelated, reflecting global environmental and developmental commitments. Correct answer is a) Both I and II are correct. 

Chapter: Biodiversity and Conservation; Topic: Patterns of Biodiversity; Subtopic: Species Richness in Amazon Rainforest

Keyword Definitions:

• Biodiversity: The total variety of living organisms present in a particular habitat or on Earth, including plants, animals, and microorganisms.

• Species Richness: The number of different species represented in an ecological community or region.

• Amazon Rainforest: The world’s largest tropical rainforest known for the highest biodiversity on Earth, located mainly in South America.

• Invertebrates: Animals without a backbone, such as insects, mollusks, and worms, forming the largest group of living organisms.

• Endemism: Ecological state of a species being unique to a defined geographic location, such as an island or a forest.

Lead Question – 2022 (Ganganagar)
Give the correct descending order of organisms with reference to their estimated number found in Amazon forest.
(a) Plants
(b) Invertebrates
(c) Fishes
(d) Mammals
(e) Birds
Choose the correct answer from the options given below:
1. (a) > (b) > (e) > (d) > (c)
2. (a) > (c) > (d) > (b) > (e)
3. (b) > (a) > (e) > (d) > (c)
4. (b) > (a) > (c) > (e) > (d)

Explanation:
The correct answer is option 3: (b) > (a) > (e) > (d) > (c). The Amazon rainforest contains the greatest biodiversity on Earth, dominated by invertebrates like insects, followed by plants, birds, mammals, and fishes. It houses millions of insect species, thousands of plant species, and diverse vertebrates, illustrating the concept of species richness and ecological stability.

1. Single Correct Answer Type
Which of the following regions is known as the “lungs of the planet”?
1. Sahara Desert
2. Amazon Rainforest
3. Siberian Taiga
4. Great Barrier Reef
Explanation: The Amazon Rainforest is called the “lungs of the planet” because it produces nearly 20% of the world’s oxygen and absorbs massive amounts of CO₂. Its dense vegetation and vast biodiversity play a vital role in maintaining Earth’s atmospheric balance. Hence, option 2 is correct.

2. Single Correct Answer Type
The Amazon rainforest contributes to global biodiversity mainly due to:
1. Low rainfall and limited plant life
2. Uniform climate and vast vegetation
3. High altitude and cold temperature
4. Low nutrient soil and sparse species
Explanation: Amazon’s biodiversity results from its warm, humid, and stable tropical climate supporting dense vegetation and ecological niches. Constant rainfall and uniform temperature favor species adaptation and speciation. Hence, option 2 is correct as the stable environment enhances diversity and sustains millions of species.

3. Single Correct Answer Type
Which type of biodiversity represents the total number of species within a region?
1. Ecological diversity
2. Genetic diversity
3. Species diversity
4. Habitat diversity
Explanation: Species diversity refers to the total number of species within a given ecosystem or region. It includes both species richness and evenness. The Amazon rainforest exhibits the highest species diversity due to the presence of millions of distinct species of animals and plants. Therefore, the correct answer is option 3.

4. Single Correct Answer Type
Which of the following is the most species-rich group in the Amazon rainforest?
1. Mammals
2. Birds
3. Invertebrates
4. Amphibians
Explanation: Invertebrates, especially insects, form the largest group of living organisms in the Amazon rainforest. They play crucial roles in pollination, decomposition, and maintaining ecological balance. Hence, option 3 is correct, as invertebrates outnumber all other groups combined, reflecting their dominant contribution to biodiversity.

5. Single Correct Answer Type
Which of the following statements is true regarding biodiversity in the Amazon forest?
1. Mammals are the most abundant group.
2. Birds outnumber invertebrates.
3. Invertebrates have the highest species diversity.
4. Plants are the least diverse organisms.
Explanation: In the Amazon rainforest, invertebrates have the highest species diversity, followed by plants, birds, and mammals. This biodiversity supports ecological processes such as nutrient cycling and pollination. Thus, option 3 is correct, as invertebrates dominate the ecosystem by sheer number and functional diversity.

6. Single Correct Answer Type
Which of the following represents a cause of high biodiversity in tropical rainforests?
1. Harsh climatic conditions
2. Low competition among species
3. Stable and warm climate
4. Limited sunlight availability
Explanation: Tropical rainforests, including the Amazon, have high biodiversity due to a stable, warm, and humid climate throughout the year. These conditions allow for continuous growth, adaptation, and evolution of new species. Therefore, option 3 is correct, as stability in temperature favors long-term species diversification.

7. Assertion-Reason Type
Assertion (A): The Amazon rainforest shows extremely high species diversity.
Reason (R): Stable climatic conditions promote speciation and ecological balance.
1. Both (A) and (R) are correct and (R) is the correct explanation of (A)
2. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
3. (A) is correct but (R) is not correct
4. (A) is not correct but (R) is correct
Explanation: The Amazon rainforest’s biodiversity arises from its consistent warm climate, high rainfall, and long evolutionary history. These factors promote niche specialization and species survival. Thus, both (A) and (R) are true, and (R) correctly explains (A). The correct answer is option 1.

8. Matching Type
Match the ecosystem with its characteristic feature:
A. Amazon Rainforest
B. Coral Reefs
C. Arctic Tundra
D. Desert
1. Highest biodiversity
2. Extreme cold and low diversity
3. Drought-adapted species
4. Marine ecosystem with high productivity
Options:
A-1, B-4, C-2, D-3
A-3, B-2, C-1, D-4
A-4, B-3, C-2, D-1
A-1, B-3, C-2, D-4
Explanation: The Amazon rainforest exhibits highest biodiversity (1), coral reefs have high marine productivity (4), Arctic tundra shows low diversity (2), and deserts have drought-resistant species (3). Thus, the correct match is A-1, B-4, C-2, D-3, highlighting different adaptive ecosystems of Earth’s biosphere.

9. Fill in the Blanks Type
The Amazon rainforest contains about ________% of the world’s known species.
1. 2%
2. 5%
3. 10%
4. 20%
Explanation: The Amazon rainforest holds nearly 20% of the world’s known species, making it the most biodiverse region on Earth. It harbors millions of insects, thousands of plants, and hundreds of bird and mammal species. Hence, option 4 is correct, representing its vast contribution to global biodiversity.

10. Choose the Correct Statements Type
Statement I: The Amazon rainforest has high biodiversity due to stable climate and nutrient-rich soil.
Statement II: Invertebrates are the most abundant species group in the Amazon.
1. Both statements are correct
2. Both statements are incorrect
3. Statement I is correct, Statement II is incorrect
4. Statement I is incorrect, Statement II is correct
Explanation: The Amazon rainforest’s biodiversity is mainly due to stable climatic conditions and not nutrient-rich soil, which is actually poor. Invertebrates dominate the ecosystem in terms of diversity. Hence, Statement I is incorrect and Statement II is correct. The correct answer is option 4.

Topic: Ecological Concepts; Subtopic: Endemism and Species Distribution

Keyword Definitions:

• Endemism: Ecological state in which a species is restricted to a specific geographic location and not naturally found elsewhere.

• Species richness: The total number of different species present in a defined area.

• Species evenness: The relative abundance of individuals among different species in an ecosystem.

• Species diversity: Combined measure of species richness and evenness in a community.

• Habitat: The natural environment in which a species lives and thrives.

• Geographical range: The area or region in which a species is naturally found.

• Biogeography: Study of the distribution of species and ecosystems in geographic space and through geological time.

• Conservation: Efforts to protect species and ecosystems from extinction or degradation.

Lead Question - 2022 (Abroad)
Endemism refers to:
1. Species richness
2. Species evenness
3. Species confined to that region
4. Species diversity
Explanation: The correct answer is Species confined to that region. Endemism describes species that are native to a specific geographic area and not naturally found elsewhere. This can occur due to geographic isolation, unique ecological conditions, or evolutionary processes. Endemic species are often highly vulnerable to habitat loss and environmental changes. They contribute significantly to global biodiversity and are important for conservation planning. Unlike species richness, evenness, or diversity, endemism specifically emphasizes the restricted geographic distribution of organisms, making it a crucial concept in biogeography and ecological studies for preserving unique flora and fauna.

1. Single Correct Answer Type:
Which of the following is an example of an endemic species?
1. Lion found in Africa and India
2. Kangaroo in Australia
3. House sparrow worldwide
4. Polar bear in Arctic and subarctic regions
Explanation: The correct answer is Kangaroo in Australia. Kangaroos are native and restricted to Australia, making them endemic to this region. Unlike lions, sparrows, or polar bears, which have wider geographic ranges, endemic species exist only in specific regions due to historical, ecological, or evolutionary factors. Endemism indicates the uniqueness of a region’s biodiversity and helps identify priority areas for conservation. These species often evolve in isolation and are sensitive to environmental changes, habitat destruction, and invasive species, making protection of their natural habitats essential for maintaining ecological balance and regional biodiversity.

2. Single Correct Answer Type:
High endemism in a region usually indicates:
1. Low species richness
2. Unique ecological conditions
3. Worldwide species distribution
4. Species evenness
Explanation: The correct answer is Unique ecological conditions. High endemism occurs where species are confined to a region due to isolation, specialized habitats, or unique environmental conditions. Such areas often have distinctive climates, geography, or evolutionary histories, promoting the emergence of endemic species. Endemism does not necessarily imply low species richness; a region can be both species-rich and highly endemic. Understanding endemism helps in prioritizing areas for biodiversity conservation, protecting species with restricted ranges, and preventing local extinctions caused by habitat loss, climate change, or invasive species, ensuring the maintenance of global biodiversity.

3. Single Correct Answer Type:
Which region is known for high plant endemism?
1. Amazon Rainforest
2. Western Ghats
3. Sahara Desert
4. Great Plains of North America
Explanation: The correct answer is Western Ghats. The Western Ghats of India are a biodiversity hotspot with a high proportion of plant species found nowhere else, making them endemic. Factors include unique topography, climate, and geological history. Unlike the Amazon or Sahara, which have lower endemic proportions, the Western Ghats’ isolation and ecological diversity support endemism. Conservation of endemic species in such regions is crucial, as their restricted distribution makes them vulnerable to habitat destruction, climate change, and human activities. Protecting these ecosystems preserves genetic diversity and ecological integrity for future generations.

4. Single Correct Answer Type:
Endemic species are most vulnerable to:
1. Global migration
2. Habitat loss
3. Abundant food sources
4. Widespread distribution
Explanation: The correct answer is Habitat loss. Endemic species are confined to specific regions; thus, destruction or alteration of their habitat can easily lead to population decline or extinction. Unlike widespread species, they cannot relocate or adapt quickly to other regions. Conservation strategies targeting habitat protection, restoration, and control of invasive species are essential for their survival. Endemic species often have specialized ecological requirements, making them indicators of ecosystem health. Preserving their habitats not only protects individual species but also maintains regional biodiversity, ecological balance, and unique evolutionary lineages.

5. Single Correct Answer Type:
Which factor does NOT contribute to endemism?
1. Geographic isolation
2. Unique ecological niches
3. Human introduction of species
4. Evolutionary adaptation
Explanation: The correct answer is Human introduction of species. Endemism arises from natural isolation, unique habitats, and evolutionary adaptation over time. Introduced species, brought by humans to new regions, are not endemic because they are not naturally confined. Geographic barriers such as mountains or islands, and specialized ecological conditions, drive endemism. Protecting endemic species requires conservation of these natural barriers and ecological niches. Human introductions can threaten endemic species through competition, predation, or disease, making it critical to manage invasive species to maintain the integrity of naturally endemic biodiversity.

6. Single Correct Answer Type:
Endemism is most often studied under which field?
1. Genetics
2. Biogeography
3. Physiology
4. Molecular biology
Explanation: The correct answer is Biogeography. Biogeography examines the distribution of species across geographic space and time, and endemism is a key concept in identifying species confined to specific regions. This field helps understand historical, ecological, and evolutionary processes that lead to restricted ranges. Knowledge of endemism aids in conservation planning, identifying biodiversity hotspots, and mitigating threats. Other fields like genetics, physiology, and molecular biology study internal traits of organisms, but the spatial restriction and regional uniqueness of species is specifically a biogeographical concern, providing critical insights for ecosystem management and preservation of endemic species.

7. Assertion-Reason Type:
Assertion (A): Islands often have high endemism.
Reason (R): Geographic isolation limits gene flow and promotes speciation.
1. Both A and R are correct, and R is the correct explanation of A
2. Both A and R are correct, but R is not the correct explanation of A
3. A is correct, R is false
4. A is false, R is true
Explanation: Correct answer is Both A and R are correct, and R is the correct explanation of A. Islands are naturally isolated, limiting immigration and gene flow. Over time, this isolation promotes speciation, resulting in species unique to those islands. Examples include the Galápagos finches and Madagascar lemurs. Endemism on islands highlights the role of geographic barriers in evolution. These species are vulnerable to environmental changes and human interference. Studying island endemism provides insights into adaptive radiation, evolutionary ecology, and informs conservation priorities to protect these uniquely evolved species and their fragile habitats.

8. Matching Type:
Match the region with its characteristic endemism:
A. Madagascar → (i) High animal endemism
B. Western Ghats → (ii) High plant endemism
C. Galápagos Islands → (iii) Island adaptive radiation
D. Amazon Rainforest → (iv) High species richness, low endemism
Options:
1. A-i, B-ii, C-iii, D-iv
2. A-ii, B-i, C-iv, D-iii
3. A-iii, B-iv, C-i, D-ii
4. A-iv, B-iii, C-ii, D-i
Explanation: Correct answer is 1. A-i, B-ii, C-iii, D-iv. Madagascar has unique animals; Western Ghats are rich in endemic plants; Galápagos Islands show adaptive radiation; Amazon is highly species-rich but many species have wider distributions. Endemism is influenced by isolation, evolutionary history,

Topic: Biodiversity Threats; Subtopic: Evil Quarter

• Evil Quarter: Term describing major threats to biodiversity causing species decline.

• Habitat loss and fragmentation: Destruction or division of natural habitats reducing living space for species.

• Over-exploitation: Excessive use of species for human needs leading to population decline.

• Alien species invasion: Introduction of non-native species disrupting local ecosystems.

• Mortality: Death rate in populations, natural or induced.

• Competition: Interaction between species or individuals for limited resources.

• Biodiversity: Variety of life in ecosystems, species, and genes.

• Conservation: Protection and management of natural resources to prevent biodiversity loss.

• Extinction: Complete disappearance of a species from Earth.

• Anthropogenic threats: Human-induced factors causing environmental degradation and species decline.

• Ecosystem disruption: Disturbances altering ecosystem structure and function, reducing species survival.

Lead Question - 2022 (Abroad)

Which of the following come under the "Evil Quarter"?

(a) Habitat loss and fragmentation
(b) Over-exploitation
(c) Alien species invasion
(d) Mortality
(e) Competition

Choose the correct answer from the options given below:

1. (a), (c) and (d)

2. (b), (c) and (d)

3. (a), (b) and (c)

Explanation: The "Evil Quarter" refers to major anthropogenic threats affecting biodiversity. Habitat loss and fragmentation, over-exploitation, and alien species invasion are primary causes. Mortality and competition are consequences or natural factors. Therefore, the correct combination from the options representing the Evil Quarter is (a), (b) and (c). Answer: 3

Q1: Which is a direct consequence of habitat fragmentation?

1. Increased population

2. Reduced genetic diversity

3. Enhanced ecosystem stability

4. Improved species survival

Explanation: Habitat fragmentation divides populations into isolated patches, reducing gene flow and genetic diversity. This leads to inbreeding and increased extinction risk. Fragmentation disrupts ecosystems rather than stabilizing them. Correct answer is reduced genetic diversity, a direct negative consequence of dividing habitats. Answer: Reduced genetic diversity. Answer: 2

Q2: Over-exploitation of species primarily leads to:

1. Population growth

2. Extinction

3. Migration

4. Speciation

Explanation: Over-exploitation occurs when humans excessively harvest species for food, medicine, or trade. Unsustainable use reduces population numbers rapidly, pushing species toward local or global extinction. Proper conservation is required to prevent species loss. Answer: Extinction. Answer: 2

Q3: Alien species invasion affects native species by:

1. Providing more food

2. Displacing native species

3. Increasing biodiversity naturally

4. Reducing mortality

Explanation: Alien species often outcompete native species for resources, introducing diseases or predation, causing population declines or local extinctions. They disrupt natural ecosystems rather than supporting biodiversity. Answer: Displacing native species. Answer: 2

Q4: Which human activity is a leading cause of habitat loss?

1. Deforestation

2. Natural disasters

3. Predation

4. Migration

Explanation: Deforestation removes forests, reducing living space for species, fragmenting habitats, and causing biodiversity decline. Other activities like predation or migration are natural processes. Human-induced habitat loss is a major anthropogenic threat contributing to the Evil Quarter. Answer: Deforestation. Answer: 1

Q5: Mortality in ecosystems can increase due to:

1. Predation alone

2. Habitat loss and pollution

3. Competition only

4. Random events only

Explanation: Mortality rises due to habitat loss, pollution, over-exploitation, and invasive species. These anthropogenic factors increase death rates beyond natural levels, threatening population stability. Natural predation contributes but human activities intensify mortality. Answer: Habitat loss and pollution. Answer: 2

Q6: Which of the following is NOT considered part of the Evil Quarter?

1. Habitat loss

2. Over-exploitation

3. Competition

4. Alien species invasion

Explanation: Competition is a natural interaction among species and not categorized under the Evil Quarter, which includes major anthropogenic threats like habitat loss, over-exploitation, and alien species invasion. Answer: Competition. Answer: 3

Q7: Assertion (A): Alien species invasion is harmful to ecosystems.
Reason (R): Non-native species may outcompete or prey on native species.

1. (A) is correct but R is not correct

2. (A) is not correct but R is correct

3. Both A and R are correct and R explains A

4. Both A and R are correct but R does not explain A

Explanation: Alien species often disrupt ecosystems by outcompeting native species, introducing diseases, or predating on local organisms. Both the assertion and reason are correct, and the reason provides the explanation for the harm caused. Answer: Both A and R are correct and R explains A. Answer: 3

Q8: Match the threats with their types:

A. Habitat loss    1. Natural
B. Over-exploitation    2. Anthropogenic
C. Alien species invasion    3. Anthropogenic
D. Predation    4. Natural

1. A-2, B-2, C-2, D-4

2. A-1, B-2, C-2, D-3

3. A-2, B-3, C-1, D-4

4. A-1, B-1, C-2, D-4

Explanation: Habitat loss, over-exploitation, and alien species invasion are human-induced threats, whereas predation is a natural ecological process. Correct matching categorizes anthropogenic versus natural factors accurately. Answer: A-2, B-2, C-2, D-4. Answer: 1

Q9: Excessive hunting or harvesting leading to species decline is called ______.

1. Habitat loss

2. Over-exploitation

3. Invasion

4. Competition

Explanation: Over-exploitation refers to unsustainable harvesting of species for food, trade, or resources. It directly reduces population numbers, sometimes causing extinction. Habitat loss or alien invasion are different threats. Proper management is required to prevent biodiversity decline. Answer: Over-exploitation. Answer: 2

Q10: Which of the following are part of the Evil Quarter?

1. Habitat loss and fragmentation

2. Over-exploitation

3. Alien species invasion

4. Competition

Explanation: The Evil Quarter consists of major anthropogenic threats causing biodiversity loss. Habitat loss, over-exploitation, and alien species invasion are included, whereas competition is a natural ecological interaction. Correct statements representing the Evil Quarter are 1, 2, and 3. Answer: 1, 2, 3

Subtopic: In-situ and Ex-situ Conservation

Keyword Definitions:
• In-situ Conservation: Conservation of species within their natural habitat and ecosystem.
• Ex-situ Conservation: Conservation of species outside their natural habitat, e.g., zoos or botanical gardens.
• Biodiversity: Variety of living organisms in an ecosystem.
• Endangered Species: Species at risk of extinction.
• Extinct Species: Species that no longer exist.
• High Risk Species: Species facing threats but not necessarily endangered.
• Protected Area: Designated region for conserving wildlife and habitats.
• Habitat: Natural environment where a species lives.
• Ecosystem: Community of organisms interacting with their environment.
• Conservation Strategies: Methods to protect biodiversity and ecosystems.

Lead Question (2022):
In-situ conservation refers to:
1. Conserve only high risk species
2. Conserve only endangered species
3. Conserve only extinct species
4. Protect and conserve the whole ecosystem

Explanation: The correct answer is 4. In-situ conservation focuses on protecting species in their natural habitats, ensuring the conservation of the whole ecosystem, including plants, animals, and microorganisms. This method maintains ecological processes, genetic diversity, and natural interactions, unlike ex-situ methods that isolate species outside their environment.

Guessed MCQs:

1. Single Correct Answer:
Which of the following is an example of in-situ conservation?
Options:
(a) National parks
(b) Zoos
(c) Seed banks
(d) Botanical gardens
Explanation: The correct answer is (a). National parks conserve species in their natural habitats, maintaining ecosystem integrity, whereas zoos, seed banks, and botanical gardens are ex-situ conservation sites.

2. Single Correct Answer:
What is the main goal of in-situ conservation?
Options:
(a) Preserve species within natural habitats
(b) Preserve species in laboratories
(c) Preserve species in captivity
(d) Preserve only endangered species
Explanation: The correct answer is (a). In-situ conservation protects species within their natural habitats, ensuring ecological processes, genetic diversity, and natural interactions, unlike ex-situ methods that isolate species.

3. Assertion-Reason MCQ:
Assertion (A): In-situ conservation maintains genetic diversity.
Reason (R): Species are protected in their natural habitats with ecological interactions intact.
Options:
(a) Both A and R are true, R explains A
(b) Both A and R are true, R does not explain A
(c) A is true, R is false
(d) A is false, R is true
Explanation: The correct answer is (a). In-situ conservation preserves species in their natural habitats, maintaining genetic diversity, ecological interactions, and natural selection pressures, which ensures long-term species survival.

4. Matching Type MCQ:
Match the conservation strategy with its example:
List - I List - II
(a) In-situ (i) Wildlife sanctuary
(b) Ex-situ (ii) Botanical garden
(c) Ex-situ (iii) Seed bank
Options:
1. a-i, b-ii, c-iii
2. a-ii, b-i, c-iii
3. a-iii, b-i, c-ii
4. a-i, b-iii, c-ii
Explanation: The correct answer is 1. In-situ conservation includes wildlife sanctuaries. Ex-situ conservation includes botanical gardens and seed banks, where species are preserved outside their natural habitats.

5. Single Correct Answer:
Which of the following is a protected area for in-situ conservation?
Options:
(a) Biosphere reserve
(b) Zoological park
(c) Aquarium
(d) Tissue culture lab
Explanation: The correct answer is (a). Biosphere reserves conserve ecosystems in their natural state. Zoological parks, aquariums, and tissue culture labs represent ex-situ conservation outside natural habitats.

6. Single Correct Answer:
In-situ conservation helps in:
Options:
(a) Maintaining ecological balance
(b) Preserving only one species
(c) Storing seeds artificially
(d) Growing plants in greenhouses
Explanation: The correct answer is (a). By conserving species in their natural habitat, in-situ conservation maintains ecological processes, food chains, and interactions, unlike artificial storage or controlled growth.

7. Fill in the Blanks:
_________ is an example of in-situ conservation where natural habitats are protected for species survival.
Options:
(a) National park
(b) Zoo
(c) Seed bank
(d) Botanical garden
Explanation: The correct answer is (a). National parks protect species within natural habitats, maintaining ecological integrity, species interactions, and long-term survival, unlike ex-situ sites such as zoos or seed banks.

8. Single Correct Answer:
Which species benefit most from in-situ conservation?
Options:
(a) All species in the protected ecosystem
(b) Only endangered species
(c) Only high-risk species
(d) Only extinct species
Explanation: The correct answer is (a). In-situ conservation protects the entire ecosystem, including common, rare, and endangered species, maintaining natural processes rather than focusing solely on threatened species.

9. Single Correct Answer:
Which of the following is NOT an in-situ conservation method?
Options:
(a) Zoo
(b) Wildlife sanctuary
(c) National park
(d) Biosphere reserve
Explanation: The correct answer is (a). Zoos are ex-situ conservation sites, while wildlife sanctuaries, national parks, and biosphere reserves protect species within natural habitats.

10. Choose the correct statements:
(a) In-situ conservation maintains natural habitats.
(b) Ex-situ conservation includes seed banks and zoos.
(c) In-situ conservation only protects endangered species.
(d) In-situ conservation ensures ecological interactions.
Options:
1. a, b, d only
2. a and c only
3. b and c only
4. All statements
Explanation: The correct answer is 1. In-situ conservation maintains natural habitats and ecological interactions. Ex-situ conservation includes seed banks and zoos. It is not limited to endangered species, protecting entire ecosystems and their biodiversity.

Subtopic: Threats to Biodiversity

Keyword Definitions:

• Habitat loss: Destruction or alteration of natural environments, reducing living space for species.

• Fragmentation: Division of ecosystems into smaller, isolated patches affecting species survival.

• Overexploitation: Excessive use of species for economic, food, or recreational purposes beyond sustainable limits.

• Alien species invasion: Introduction of non-native species that disrupt native ecosystems and outcompete indigenous species.

• Co-extinction: The loss of one species causing dependent species to go extinct.

• Biodiversity: Variety of life in all forms and levels including genes, species, and ecosystems.

• Competition: Interaction between organisms for limited resources.

• Natality: Birth rate in a population.

• Population explosion: Rapid increase in population size due to high birth rate and low mortality.

Lead Question (2022)
Habitat loss and fragmentation, over exploitation, alien species invasion and co-extinction are causes for :
(1) Competition
(2) Biodiversity loss
(3) Natality
(4) Population explosion

Explanation:
All listed factors like habitat loss, fragmentation, overexploitation, alien species invasion, and co-extinction directly reduce species diversity and threaten ecosystem balance. These processes result in decreased genetic, species, and ecosystem diversity. Correct answer is (2).

1. Single Correct Answer MCQ:
Which of the following is an example of overexploitation?
(1) Deforestation
(2) Poaching of tigers
(3) Invasive species introduction
(4) Natural disasters

Explanation:
Overexploitation occurs when humans excessively harvest or hunt species. Poaching of tigers for skins and body parts exemplifies this. Deforestation is habitat loss, invasive species introduction is alien invasion, and natural disasters are unrelated to overexploitation. Correct answer is (2).

2. Single Correct Answer MCQ:
Alien species invasion can lead to:
(1) Habitat restoration
(2) Extinction of native species
(3) Increase in natality
(4) Enhanced pollination

Explanation:
Non-native species often compete with indigenous species for resources, sometimes preying on them, leading to local or global extinction. Alien species rarely restore habitat or increase natality of natives. Correct answer is (2).

3. Single Correct Answer MCQ:
Fragmentation primarily affects:
(1) Water quality
(2) Connectivity of habitats
(3) Atmospheric CO2
(4) Soil fertility

Explanation:
Fragmentation divides habitats into isolated patches, reducing connectivity, limiting gene flow, and increasing species vulnerability. While it can indirectly affect soil or water, the primary impact is on habitat connectivity. Correct answer is (2).

4. Single Correct Answer MCQ:
Co-extinction occurs when:
(1) Two species compete
(2) Loss of one species causes dependent species to vanish
(3) Natality exceeds mortality
(4) Habitat is restored

Explanation:
Co-extinction happens when the extinction of one species directly causes extinction of another dependent species, such as a parasite or mutualistic partner. Competition or natality changes are not co-extinction. Correct answer is (2).

5. Single Correct Answer MCQ:
Which is a major cause of global biodiversity loss?
(1) Climate change
(2) Overexploitation
(3) Habitat destruction
(4) All of the above

Explanation:
Biodiversity loss is driven by multiple factors including climate change, overexploitation, and habitat destruction. All these factors reduce species populations and genetic diversity globally. Correct answer is (4).

6. Single Correct Answer MCQ:
Which of the following is not a threat to biodiversity?
(1) Habitat restoration
(2) Invasive species
(3) Overexploitation
(4) Fragmentation

Explanation:
Habitat restoration aims to restore ecosystems and biodiversity, so it is not a threat. In contrast, invasive species, overexploitation, and fragmentation reduce species populations. Correct answer is (1).

7. Assertion-Reason MCQ:
Assertion (A): Habitat loss leads to decline in species diversity.
Reason (R): Fragmentation isolates populations, reducing gene flow.
Options:
(1) Both A and R are correct and R explains A
(2) A correct, R incorrect
(3) A incorrect, R correct
(4) Both A and R incorrect

Explanation:
Habitat loss reduces living space, causing population decline, and fragmentation isolates populations, reducing genetic diversity. Both statements are correct, and the Reason explains the Assertion. Correct answer is (1).

8. Matching Type MCQ:
Match threat with its example:
A. Habitat loss — 1. Deforestation
B. Overexploitation — 2. Tiger poaching
C. Alien invasion — 3. Lantana spread
D. Co-extinction — 4. Extinction of pollinator dependent plant
Options:
(1) A–1, B–2, C–3, D–4
(2) A–2, B–1, C–4, D–3
(3) A–1, B–3, C–2, D–4
(4) A–3, B–4, C–1, D–2

Explanation:
Habitat loss example: deforestation. Overexploitation: tiger poaching. Alien invasion: Lantana spread. Co-extinction: loss of pollinator leads to dependent plant extinction. Correct matching is A–1, B–2, C–3, D–4. Correct answer is (1).

9. Fill in the Blanks:
Introduction of non-native species that disrupt ecosystems is called ________.
(1) Fragmentation
(2) Alien species invasion
(3) Overexploitation
(4) Co-extinction

Explanation:
Alien species invasion occurs when non-native species are introduced, competing with natives and causing ecological imbalance. Fragmentation divides habitats, overexploitation depletes populations, co-extinction is dependent species loss. Correct answer is (2).

10. Choose the Correct Statements:
(a) Habitat fragmentation reduces gene flow
(b) Overexploitation leads to population decline
(c) Alien species introduction helps native species
(d) Co-extinction can occur if a keystone species disappears
Options:
(1) a, b, d
(2) a and c only
(3) b and c only
(4) all of the above

Explanation:
Habitat fragmentation reduces gene flow (a), overexploitation reduces populations (b), and co-extinction occurs when dependent species are affected (d). Alien species introduction usually harms natives, so c is incorrect. Correct answer is (1).

Subtopic: Ex Situ and In Situ Conservation

Keyword Definitions:

• Conservation: The protection, preservation, and management of biodiversity to ensure its sustainable use.

• Ex Situ Conservation: Conservation of species outside their natural habitat through methods like zoos, seed banks, and cryopreservation.

• In Situ Conservation: Protection of species within their natural habitats such as national parks and sanctuaries.

• Cryopreservation: Preserving cells or tissues at very low temperatures to maintain genetic material.

• Micropropagation: A technique to rapidly multiply plants using tissue culture under controlled conditions.

• National Park: A protected area established to conserve wildlife and ecosystems in their natural setting.

• In Vitro Fertilization (IVF): Fertilization of an egg outside the body, often used in animal breeding and human reproduction.

• Seed Bank: Facility used to store seeds to preserve genetic diversity for future restoration.

• Gene Bank: Repository that preserves genetic material such as seeds, sperms, and tissues.

• Botanical Garden: A place where diverse plant species are cultivated and studied for conservation and education.

• Wildlife Sanctuary: Natural area where animals are protected from hunting and habitat destruction.

Lead Question - 2022

Which of the following is not a method of ex situ conservation?

(1) National Parks

(2) Micropropagation

(3) Cryopreservation

(4) In vitro fertilization

Explanation: Ex situ conservation occurs outside natural habitats through techniques like cryopreservation, micropropagation, and IVF. National parks represent in situ conservation as species are protected in their natural environment. Therefore, option (1) National Parks is not an ex situ method. Correct answer is option 1.

1. Single Correct Answer: Which of the following represents in situ conservation?

a) Biosphere Reserve

b) Cryopreservation

c) Seed Bank

d) Botanical Garden

Explanation: In situ conservation protects species within their natural habitats, such as biosphere reserves and sanctuaries. Cryopreservation and seed banks are ex situ approaches. Correct answer is option a.

2. Single Correct Answer: Which of these is not an ex situ conservation example?

a) Zoological Park

b) Gene Bank

c) National Park

d) Tissue Culture Lab

Explanation: Ex situ methods include gene banks, zoos, and labs. National parks protect species in natural habitats, hence in situ. Correct answer is option c.

3. Single Correct Answer: In cryopreservation, biological material is stored at:

a) 0°C

b) –196°C

c) 4°C

d) –20°C

Explanation: Cryopreservation stores biological materials such as sperms, eggs, and tissues at extremely low temperatures, generally in liquid nitrogen at –196°C to prevent degradation. Correct answer is option b.

4. Single Correct Answer: Which of the following is a man-made ex situ conservation site?

a) Wildlife Sanctuary

b) Biosphere Reserve

c) Botanical Garden

d) National Park

Explanation: Botanical gardens are man-made areas designed to grow and conserve rare plant species outside their natural environment. Correct answer is option c.

5. Single Correct Answer: Gene banks are mainly established for:

a) Storing genetic material

b) Promoting tourism

c) Harvesting crops

d) Preserving fossil fuels

Explanation: Gene banks are used to store seeds, sperms, or tissues to preserve genetic diversity for future use and restoration programs. Correct answer is option a.

6. Single Correct Answer: Sacred groves are examples of:

a) Ex situ conservation

b) In situ conservation

c) Both

d) None

Explanation: Sacred groves are patches of forest protected by communities due to cultural and religious beliefs, representing in situ conservation. Correct answer is option b.

7. Assertion-Reason:

Assertion (A): Cryopreservation helps conserve endangered species.

Reason (R): It stores viable gametes and tissues at very low temperatures for future use.

a) Both A and R true, R explains A

b) Both A and R true, R does not explain A

c) A true, R false

d) A false, R true

Explanation: Cryopreservation maintains biological samples viable for decades, supporting conservation of endangered species. Both statements are true and reason correctly explains assertion. Correct answer is option a.

8. Matching Type:

Match the conservation method with its example:

a) In situ — i) National Park

b) Ex situ — ii) Zoo

Options:

1. a-i, b-ii

2. a-ii, b-i

3. a-i, b-i

4. a-ii, b-ii

Explanation: In situ includes national parks where organisms live naturally, while ex situ includes zoos for artificial protection. Correct answer is option 1.

9. Fill in the Blanks: The _______ technique helps conserve plant varieties through tissue culture.

a) Micropropagation

b) Gene editing

c) Cloning

d) Polymerization

Explanation: Micropropagation is a tissue culture method to rapidly multiply and conserve plant species under controlled laboratory conditions. Correct answer is option a.

10. Choose the correct statements:

1) Ex situ conservation occurs outside natural habitat.

2) In vitro fertilization is an ex situ method.

3) National parks represent in situ conservation.

4) Cryopreservation involves storing materials at room temperature.

Explanation: Statements 1, 2, and 3 are correct. Cryopreservation uses very low temperatures, not room temperature. Correct choice includes 1, 2, and 3.

Topic: Invasive Species and Their Impact
Subtopic: Ornamental Plants Becoming Invasive

Keyword Definitions:

• Invasive species: Non-native species that spread rapidly and harm local ecosystems.

• Parthenium hysterophorus: An aggressive weed introduced for ornamental purposes causing ecological and health problems.

• Eichhornia crassipes: Water hyacinth, an aquatic invasive plant affecting water bodies.

• Prosopis juliflora: Thorny shrub/tree introduced for afforestation, now invasive in arid areas.

• Trapa spinosa: Water chestnut, can become invasive in wetlands.

• Ornamental plants: Plants introduced for decorative purposes in gardens or landscapes.

• Weed: Plant growing where it is not wanted, often competing with crops or native species.

• Ecological impact: Changes in species composition, nutrient cycling, or habitat quality caused by invasives.

• Native species: Species naturally occurring in a region or ecosystem.

• Biological invasion: Process where non-native species spread and establish in new environments.

• Control measures: Strategies used to manage invasive species, such as mechanical removal or biological control.

Lead Question - 2020 (COVID Reexam)

A species that was introduced for ornamentation but has become a troublesome weed in India :

1. Parthenium hysterophorus
2. Eichhornia crassipes
3. Prosopis juliflora
4. Trapa Spinosa

Explanation: Parthenium hysterophorus, originally introduced as an ornamental plant, has become highly invasive in India. It spreads quickly, affects crop productivity, causes allergies, and outcompetes native vegetation. Eichhornia and Trapa are aquatic invasives; Prosopis juliflora was for afforestation. Hence, the correct answer is option 1 (Parthenium hysterophorus).

1. Single Correct Answer: Which of the following is an aquatic invasive plant in India?
a) Parthenium hysterophorus
b) Eichhornia crassipes
c) Prosopis juliflora
d) Lantana camara

Explanation: Eichhornia crassipes, water hyacinth, grows rapidly in water bodies, blocking sunlight and depleting oxygen. Parthenium and Lantana are terrestrial, Prosopis is a shrub/tree. Correct answer is option b.

2. Single Correct Answer: Prosopis juliflora was introduced for:
a) Ornamental purpose
b) Afforestation in arid areas
c) Aquatic control
d) Medicinal usage

Explanation: Prosopis juliflora was introduced in arid areas to prevent desertification and aid afforestation. It has become invasive in many regions. Option b is correct.

3. Single Correct Answer: Which invasive species causes allergies in humans?
a) Prosopis juliflora
b) Parthenium hysterophorus
c) Eichhornia crassipes
d) Trapa spinosa

Explanation: Parthenium hysterophorus releases pollen and toxic compounds that cause dermatitis and respiratory issues. Other invasives do not commonly cause human allergies. Option b is correct.

4. Single Correct Answer: Lantana camara is invasive mainly because:
a) It is aquatic
b) It forms dense thickets
c) It grows in deserts
d) It produces edible fruits

Explanation: Lantana camara forms dense thickets, outcompetes native flora, and reduces grazing land. It is terrestrial, not aquatic or desert-specific. Option b is correct.

5. Single Correct Answer: Eichhornia crassipes affects ecosystems by:
a) Blocking sunlight in water
b) Producing toxins in soil
c) Increasing terrestrial biodiversity
d) Stabilizing desert soils

Explanation: Water hyacinth grows on water surfaces, blocks sunlight, reduces oxygen, affecting aquatic life. It does not stabilize soils or enhance terrestrial biodiversity. Option a is correct.

6. Single Correct Answer: Trapa spinosa is problematic because:
a) It invades water bodies
b) It forms forests in deserts
c) It causes human allergies
d) It is beneficial for crops

Explanation: Trapa spinosa, a floating aquatic plant, can clog water bodies, affecting irrigation and biodiversity. It does not form desert forests or cause allergies. Option a is correct.

7. Assertion-Reason:
Assertion (A): Parthenium hysterophorus is a major weed in India.
Reason (R): It was introduced for ornamental purposes.

a) Both A and R true, R explains A
b) Both A and R true, R does not explain A
c) A true, R false
d) A false, R true

Explanation: Parthenium hysterophorus is now a major invasive weed. Its introduction for ornamentation led to uncontrolled spread, causing ecological and health issues. Both assertion and reason are correct, with reason explaining the assertion. Option a is correct.

8. Matching Type: Match the species with type of problem:
Column I: a) Parthenium, b) Prosopis, c) Eichhornia, d) Trapa
Column II: i) Aquatic weed, ii) Allergens, iii) Desert invasive, iv) Floating weed

Options:
1. a-ii, b-iii, c-i, d-iv
2. a-iii, b-ii, c-iv, d-i
3. a-i, b-iv, c-iii, d-ii
4. a-ii, b-i, c-iii, d-iv

Explanation: Parthenium causes allergens (ii), Prosopis invades arid areas (iii), Eichhornia is aquatic (i), Trapa is floating (iv). Correct match is option 1.

9. Fill in the Blanks: _______ was introduced for ornamentation but became invasive, while _______ was introduced for afforestation.
a) Parthenium, Prosopis
b) Eichhornia, Trapa
c) Prosopis, Parthenium
d) Lantana, Eichhornia

Explanation: Parthenium was for ornamental use but became invasive, Prosopis juliflora was introduced for afforestation in arid regions. Option a is correct.

10. Choose the correct statements:
1) Parthenium hysterophorus is invasive
2) Eichhornia crassipes is aquatic
3) Prosopis juliflora is invasive in arid regions
4) Trapa spinosa is a floating aquatic plant

Explanation: All statements are correct; Parthenium and Prosopis are terrestrial invasives, Eichhornia and Trapa are aquatic. Option (1,2,3,4) is correct.

Topic: Methods of Conservation
Subtopic: In situ and Ex situ conservation

Keyword Definitions:

• In situ conservation: Protection of species in their natural habitats, maintaining ecosystem integrity.

• Ex situ conservation: Conservation of species outside their natural habitats, e.g., seed banks, cryopreservation.

• Biosphere Reserve: Protected area preserving biodiversity and ecological processes.

• Sacred groves: Forest patches protected by local cultural or religious practices.

• Seed bank: Facility for storing seeds under controlled conditions for future use.

• Cryopreservation: Storage of biological material at ultra-low temperatures for long-term conservation.

• Conservation approach: Strategy used to prevent biodiversity loss.

• Method of conservation: Specific technique implemented under a conservation approach.

• Biodiversity: Variety of life forms in a given ecosystem or region.

• Ex situ methods: Include botanical gardens, zoos, seed banks, cryopreservation.

• In situ methods: Include national parks, wildlife sanctuaries, biosphere reserves.

Lead Question - 2020 (COVID Reexam)

In the following, in each set, a conservation approach and an example of a method of conservation are given:

(a) In situ conservation - Biosphere Reserve
(b) Ex situ conservation - Sacred groves
(c) In situ conservation - Seed bank
(d) Ex situ conservation - Cryopreservation

Select the option with the correct match of approach and method :

1. (a) and (c)
2. (a) and (d)
3. (b) and (d)
4. (a) and (b)

Explanation: In situ conservation involves protecting species in their natural habitats. Biosphere reserves are classic in situ examples. Seed banks, though storing genetic material, are ex situ, while cryopreservation is also ex situ. Sacred groves are in situ, not ex situ. Therefore, the correct match is option 1 (a) and (c).

1. Single Correct Answer: Which of the following is an ex situ conservation method?
a) National park
b) Botanical garden
c) Wildlife sanctuary
d) Biosphere reserve

Explanation: Botanical gardens conserve plant species outside their natural habitats, making them an ex situ method. National parks, wildlife sanctuaries, and biosphere reserves are in situ approaches. Option (b) is correct.

2. Single Correct Answer: Sacred groves are primarily conserved due to:
a) Religious and cultural beliefs
b) Scientific research
c) Urban planning
d) Commercial forestry

Explanation: Sacred groves are patches of forest protected traditionally due to religious or cultural beliefs, maintaining local biodiversity. Scientific research and urban planning are secondary. Option (a) is correct.

3. Single Correct Answer: Cryopreservation is mainly used for:
a) Preserving seeds at normal temperatures
b) Long-term storage of genetic material at ultra-low temperatures
c) Protecting animals in wildlife sanctuaries
d) Planting native species in situ

Explanation: Cryopreservation stores cells, seeds, or tissues at extremely low temperatures to maintain viability for long-term conservation, an ex situ technique. Option (b) is correct.

4. Single Correct Answer: Biosphere reserves are designed to:
a) Preserve biodiversity and ecological processes in natural habitats
b) Store genetic material outside natural habitats
c) Develop commercial plantations
d) Promote urban biodiversity only

Explanation: Biosphere reserves protect ecosystems and species in situ, maintaining ecological interactions. They are not for ex situ storage or commercial purposes. Option (a) is correct.

5. Single Correct Answer: Seed banks help in:
a) Conservation of endangered plant species
b) Increasing habitat area
c) Planting forests in biosphere reserves
d) Urban landscaping

Explanation: Seed banks conserve genetic material of endangered or important plants outside their natural habitat, allowing future restoration. Option (a) is correct.

6. Single Correct Answer: Which is an in situ conservation example?
a) Cryopreservation
b) Botanical garden
c) Wildlife sanctuary
d) Seed bank

Explanation: Wildlife sanctuaries protect species in their natural environment, representing in situ conservation. Botanical gardens, seed banks, and cryopreservation are ex situ. Option (c) is correct.

7. Assertion-Reason:
Assertion (A): Ex situ conservation is essential for critically endangered species.
Reason (R): Species are protected outside their natural habitats under controlled conditions.

a) Both A and R true, R explains A
b) Both A and R true, R does not explain A
c) A true, R false
d) A false, R true

Explanation: Ex situ conservation allows protection of critically endangered species in controlled environments, which may not survive in the wild. Both assertion and reason are correct, with reason explaining assertion. Option (a) is correct.

8. Matching Type: Match conservation approaches with examples:
Column I: a) In situ, b) Ex situ, c) In situ, d) Ex situ
Column II: i) National park, ii) Cryopreservation, iii) Sacred grove, iv) Seed bank

Options:
1. a-i, b-ii, c-iii, d-iv
2. a-ii, b-i, c-iii, d-iv
3. a-i, b-iv, c-iii, d-ii
4. a-iii, b-ii, c-i, d-iv

Explanation: In situ includes national parks and sacred groves, ex situ includes cryopreservation and seed banks. Correct match is option 1.

9. Fill in the Blanks: _______ conservation protects species in their natural habitat, whereas _______ conservation stores genetic material outside natural habitats.
a) Ex situ, In situ
b) In situ, Ex situ
c) Cryopreservation, Biosphere Reserve
d) Seed bank, Sacred grove

Explanation: In situ conservation protects species in their natural habitats; ex situ conservation stores genetic material outside habitats, like seed banks or cryopreservation. Option (b) is correct.

10. Choose the correct statements:
1) Biosphere reserves are in situ conservation
2) Cryopreservation is an ex situ technique
3) Sacred groves are in situ conservation
4) Seed banks are ex situ conservation

Explanation: All statements are correct. Biosphere reserves and sacred groves are in situ; seed banks and cryopreservation are ex situ techniques. Option (1,2,3,4) is correct.

Topic: Biodiversity and Species-Area Relationship
Subtopic: Species richness vs area explored

Keyword Definitions:

• Species richness: Number of different species present in a given area.

• Area explored: Geographic extent over which species are sampled.

• Alexander von Humboldt: Naturalist who studied biodiversity and species distribution patterns.

• Biodiversity: Variety of living organisms in an ecosystem or region.

• Species-area relationship: Ecological principle describing how species richness increases with area.

• Limit: Maximum point beyond which species richness does not increase significantly.

• Sampling: Method of studying species in a given area.

• Exploration: Survey of a region for species documentation.

• Ecological pattern: Predictable distribution of species across spatial scales.

• Habitat heterogeneity: Variety of microhabitats contributing to species richness.

• Plateau effect: Species richness increase slows after certain area coverage.

Lead Question - 2020 (COVID Reexam)

According to Alexander von Humboldt :

1. Species richness decreases with increasing area of exploration
2. Species richness increases with the increasing area, but only up to limit
3. There is no relationship between species richness and area explored
4. Species richness goes on increasing with increasing area of exploration

Explanation: Humboldt observed that species richness generally increases with area explored but only up to a certain limit, after which additional area adds few or no new species. This principle reflects the species-area relationship and plateau effect. Therefore, option 2 is correct.

1. Single Correct Answer: Which factor influences species richness most directly?
a) Area of habitat
b) Altitude alone
c) Soil type alone
d) Single climatic factor

Explanation: Area of habitat strongly influences species richness because larger areas provide more niches and resources. While altitude, soil, and climate matter, they indirectly affect richness. Option (a) is correct.

2. Single Correct Answer: The plateau effect in species richness occurs due to:
a) Habitat saturation
b) Low precipitation
c) Increased predation
d) Random extinction events

Explanation: As area increases, initially species richness rises rapidly, but eventually habitat saturation occurs, and fewer new species are added. This plateau effect explains the leveling off of richness. Option (a) is correct.

3. Single Correct Answer: Which model explains species-area relationship?
a) Logistic model
b) Power-law model
c) Exponential decay model
d) Linear regression

Explanation: The power-law model describes how species richness increases with area using S = cA^z, where S is species number and A is area. It is widely applied in ecology. Option (b) is correct.

4. Single Correct Answer: Species richness is generally higher in:
a) Small islands
b) Large contiguous habitats
c) Harsh deserts
d) Urban areas

Explanation: Larger contiguous habitats contain diverse microhabitats and resources, supporting higher species richness. Small islands and deserts have fewer niches, while urban areas are highly disturbed. Option (b) is correct.

5. Single Correct Answer: Alexander von Humboldt is known for:
a) Genetic inheritance laws
b) Studying biodiversity patterns
c) Cell theory
d) Photosynthesis mechanism

Explanation: Humboldt studied geographic distribution of species, ecosystem diversity, and environmental influences on richness. His work laid foundations for biogeography. Option (b) is correct.

6. Single Correct Answer: Which factor does NOT directly affect species richness?
a) Exploration area
b) Habitat heterogeneity
c) Human population density
d) Microclimatic variation

Explanation: Human population density may indirectly affect richness but does not directly determine species richness. Area, heterogeneity, and microclimate have immediate effects on species numbers. Option (c) is correct.

7. Assertion-Reason:
Assertion (A): Larger areas support more species.
Reason (R): Larger areas contain diverse habitats and resources.

a) Both A and R true, R explains A
b) Both A and R true, R does not explain A
c) A true, R false
d) A false, R true

Explanation: Larger areas offer more niches and resources, supporting more species. Both assertion and reason are correct, with reason explaining assertion. Option (a) is correct.

8. Matching Type: Match region with expected species richness:
Column I: a) Tropical rainforest, b) Desert, c) Temperate forest, d) Small island
Column II: i) High, ii) Low, iii) Medium, iv) Low

Options:
1. a-i, b-ii, c-iii, d-iv
2. a-ii, b-i, c-iii, d-iv
3. a-iii, b-iv, c-i, d-ii
4. a-i, b-iii, c-ii, d-iv

Explanation: Tropical rainforests have high richness, deserts and small islands low, temperate forests medium richness. Option 1 is correct.

9. Fill in the Blanks: Species richness generally _______ with increasing _______ of area explored.
a) decreases, elevation
b) increases, area
c) remains constant, time
d) decreases, temperature

Explanation: Species richness increases as area explored increases because larger areas provide more habitats and niches, allowing more species to coexist. Option (b) is correct.

10. Choose the correct statements:
1) Species richness increases with area up to a limit
2) Larger areas have higher habitat heterogeneity
3) Plateaus occur in species-area relationship
4) Species richness always decreases with area

Explanation: Statements 1, 2, 3 are correct. Species richness initially increases with area but plateaus eventually. Statement 4 is incorrect. Therefore, option (1,2,3) is correct.

Subtopic: Patterns of Biodiversity

Keyword Definitions:

• Biodiversity: Variety of life at genetic, species, and ecosystem levels.

• Species diversity: The number and variety of species present in a region.

• Amazon forests: Largest tropical rainforest, rich in flora and fauna diversity.

• Western Ghats: Biodiversity hotspot in India with many endemic species.

• Himalayas: Mountain ecosystem with unique but relatively lower species diversity.

• Endemic species: Species found only in a particular region.

• Hotspot: Region rich in endemic species under threat of extinction.

Lead Question - 2020

Which of the following regions of the globe exhibits highest species diversity?

(1) Himalayas
(2) Amazon forests
(3) Western Ghats of India
(4) Madagascar

Explanation: The correct answer is (2) Amazon forests. The Amazon rainforest, called the "lungs of the planet," contains the world’s highest biodiversity. It houses nearly 10% of all known species, with millions of insects, plants, and vertebrates. Favorable climate, high productivity, and stable ecosystems contribute to this unparalleled species richness globally.

1. Species diversity generally increases:
(1) Towards the poles
(2) Towards the equator
(3) In deserts
(4) In alpine regions
Explanation: The correct answer is (2) Towards the equator. Biodiversity shows a latitudinal gradient, with tropical regions hosting the greatest species diversity due to stable climate, abundant sunlight, and longer evolutionary time. Polar regions have fewer species because of harsh climatic conditions, limited resources, and lower productivity compared to equatorial regions.

2. Which country is known as a "megadiverse" country?
(1) India
(2) Greenland
(3) Iceland
(4) Finland
Explanation: The correct answer is (1) India. India is among the 17 megadiverse countries in the world, harboring nearly 7–8% of global biodiversity. With varied ecosystems like Himalayas, Indo-Gangetic plains, deserts, forests, wetlands, and coasts, India supports thousands of endemic species, making it a biodiversity hotspot of global importance.

3. Which biome has the lowest biodiversity?
(1) Desert
(2) Tropical rainforest
(3) Temperate forest
(4) Coral reef
Explanation: The correct answer is (1) Desert. Deserts have the lowest biodiversity because of extreme aridity, high temperature fluctuations, and scarce resources. Only specialized plants like cacti and animals like camels survive here. In contrast, tropical rainforests and coral reefs support the highest biodiversity due to rich nutrients and stable climatic conditions.

4. The Western Ghats are recognized as:
(1) Endangered zone
(2) Biodiversity hotspot
(3) Tundra ecosystem
(4) Grassland
Explanation: The correct answer is (2) Biodiversity hotspot. The Western Ghats of India are one of the 36 global biodiversity hotspots. They harbor thousands of plant and animal species, many of which are endemic. Human activities like deforestation, agriculture, and urbanization threaten these ecosystems, necessitating urgent conservation efforts to preserve biodiversity.

5. Coral reefs are often called:
(1) Deserts of the sea
(2) Rainforests of the sea
(3) Polar beds
(4) Sandy ecosystems
Explanation: The correct answer is (2) Rainforests of the sea. Coral reefs are extremely diverse marine ecosystems supporting thousands of fish, mollusks, corals, and other organisms. Like tropical rainforests, they exhibit high species richness and productivity. Coral reefs are fragile and highly sensitive to pollution, overfishing, and global warming-induced bleaching.

6. The Himalayas represent which type of biodiversity?
(1) Genetic diversity
(2) Ecosystem diversity
(3) Low diversity
(4) Marine diversity
Explanation: The correct answer is (2) Ecosystem diversity. The Himalayas support diverse ecosystems ranging from alpine meadows to temperate forests and glaciers. They harbor unique species adapted to cold and high altitudes. Although species diversity is lower compared to tropical regions, the ecosystem diversity in the Himalayas is globally significant and ecologically valuable.

7. Assertion-Reason: Assertion: Tropical rainforests have the highest species diversity. Reason: They provide stable environmental conditions and high productivity.
(1) Both A and R true, R correct explanation
(2) Both A and R true, R not correct explanation
(3) A true, R false
(4) A false, R true
Explanation: The correct answer is (1). Tropical rainforests exhibit highest biodiversity due to stable climate, abundant solar energy, high productivity, and longer evolutionary history. These factors ensure continuous availability of food, water, and shelter, allowing coexistence of a vast number of species without frequent environmental disruptions.

8. Match the following ecosystems with their biodiversity status:
(a) Tropical rainforest (i) Highest diversity
(b) Desert (ii) Lowest diversity
(c) Coral reefs (iii) High marine diversity
(d) Temperate forest (iv) Moderate diversity
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-i, c-iv, d-iii
(3) a-iii, b-iv, c-i, d-ii
(4) a-iv, b-iii, c-ii, d-i
Explanation: The correct answer is (1). Tropical rainforests show highest biodiversity, deserts show lowest, coral reefs have high marine diversity, and temperate forests show moderate species richness. These patterns reflect climatic stability, nutrient availability, and adaptation strategies of organisms inhabiting each ecosystem type globally.