Animal Tissues

NEET UG Biology 2024 (Jhajjhar)

Subtopic: Epithelial Tissue

Keyword Definitions:

• Epithelial tissue: Tissue that covers body surfaces and lines internal organs.

• Cilia: Microscopic hair-like structures aiding in movement of substances.

• Compound epithelium: Multilayered epithelium meant for protection.

• Exocrine glands: Glands that release secretions through ducts to epithelial surfaces.

• Nasal epithelium: Specialized epithelial tissue lining the nasal cavity.

Lead Question – 2024 (Jhajjhar)

The epithelial tissue has the following features:

A. Bear cilia on their free surface.

B. Provides a lining for some parts of body.

C. Compound epithelium is multilayered meant for limited role in secretion and absorption.

D. Located in the tip of nose.

E. Exocrine glands possess epithelial tissue.

Choose the most appropriate answer from the options given below:

1. B, D and E only

2. A, B and C only

3. B, C and E only

4. C, D and E only

Explanation:

The correct answer is 3. B, C and E only. Epithelial tissue forms protective linings, covers external and internal surfaces, and lines ducts of glands. Compound epithelium is multilayered with protective function and limited absorption or secretion. Exocrine glands have epithelial origin. Ciliated epithelium lines respiratory tract, not the nasal tip. Hence, options B, C, and E are correct.

Guessed Questions:

1. Which of the following epithelial types lines kidney tubules?

1. Simple cuboidal epithelium

2. Simple squamous epithelium

3. Columnar epithelium

4. Stratified epithelium

Explanation:

The correct answer is 1. Simple cuboidal epithelium. Kidney tubules are lined by simple cuboidal cells specialized for secretion and absorption. These cells have centrally located nuclei and microvilli that increase surface area. Their arrangement supports selective reabsorption and secretion functions crucial for urine formation and osmotic balance.

2. Which epithelial tissue forms the walls of alveoli in lungs?

1. Simple cuboidal

2. Simple squamous

3. Stratified squamous

4. Columnar epithelium

Explanation:

The correct answer is 2. Simple squamous epithelium. It is thin, flat, and allows diffusion of gases between alveoli and capillaries. This structure minimizes the diffusion distance and maximizes gas exchange efficiency essential for respiration, thus forming the structural basis of alveolar walls in lungs.

3. Which epithelial tissue lines the inner surface of the stomach?

1. Simple columnar epithelium

2. Simple squamous epithelium

3. Transitional epithelium

4. Stratified cuboidal epithelium

Explanation:

The correct answer is 1. Simple columnar epithelium. It contains tall, secretory cells responsible for mucus and digestive enzyme secretion. These cells protect the stomach lining from acidic gastric juices. The presence of goblet cells ensures lubrication, aiding smooth passage of food and protection of mucosal surfaces.

4. Which epithelial tissue is present in urinary bladder allowing stretchability?

1. Transitional epithelium

2. Stratified squamous

3. Columnar epithelium

4. Cuboidal epithelium

Explanation:

The correct answer is 1. Transitional epithelium. Transitional epithelium lines the urinary bladder and ureters. It is multilayered, capable of stretching and recoiling as the bladder fills and empties. This property prevents tearing and maintains the barrier between urine and underlying tissues during bladder expansion.

5. Which of the following is a characteristic of glandular epithelium?

1. Absence of basement membrane

2. Secretion of substances

3. Protective covering

4. Locomotion

Explanation:

The correct answer is 2. Secretion of substances. Glandular epithelium consists of secretory cells that produce mucus, enzymes, and hormones. Depending on presence or absence of ducts, glands may be exocrine or endocrine. This epithelium originates from surface epithelium through invagination or specialization for secretion functions.

6. Which of the following is not a feature of epithelial tissue?

1. Cells have intercellular spaces

2. Cells rest on basement membrane

3. Cells show polarity

4. Lack of blood vessels

Explanation:

The correct answer is 1. Cells have intercellular spaces. Epithelial cells are tightly packed with minimal intercellular spaces, forming continuous sheets. They lack blood vessels and rely on diffusion from underlying tissues. The basement membrane provides support and polarity ensures directional secretion and absorption.

7. Assertion-Reason Type:

Assertion (A): Stratified squamous epithelium protects underlying tissues.

Reason (R): It has multiple layers of keratinized cells that prevent wear and tear.

1. Both (A) and (R) are true, and (R) is correct explanation.

2. Both (A) and (R) are true, but (R) is not correct explanation.

3. (A) true, (R) false.

4. (A) false, (R) true.

Explanation:

The correct answer is 1. Both (A) and (R) are true, and (R) is correct explanation. Stratified squamous epithelium consists of multiple layers, where outer keratinized cells resist abrasion. Found in skin and esophagus, it prevents mechanical injury, dehydration, and infection effectively.

8. Matching Type:

Match the following:

Column I - Type of Epithelium

A. Simple Squamous

B. Columnar

C. Cuboidal

D. Ciliated Epithelium

Column II - Location

1. Kidney tubules

2. Alveoli

3. Fallopian tube

4. Stomach

Options:

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

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

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

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

Explanation:

The correct answer is A-2, B-4, C-1, D-3. Simple squamous epithelium forms alveoli for gas exchange. Columnar epithelium lines stomach for secretion. Cuboidal epithelium lines kidney tubules for absorption. Ciliated epithelium in fallopian tubes helps movement of ovum toward uterus.

9. Fill in the Blanks:

__________ epithelium lines the blood vessels and heart chambers.

1. Endothelium

2. Mesothelium

3. Transitional epithelium

4. Columnar epithelium

Explanation:

The correct answer is 1. Endothelium. Endothelium is a simple squamous epithelium lining inner surfaces of blood vessels and heart chambers. It ensures smooth blood flow, reduces friction, and plays vital roles in exchange of materials and maintenance of vascular homeostasis.

10. Choose the Correct Statements (Statement I & II):

Statement I: Basement membrane separates epithelium from underlying connective tissue.

Statement II: Epithelium is highly vascular.

1. Both statements are true.

2. Both statements are false.

3. Statement I true, Statement II false.

4. Statement I false, Statement II true.

Explanation:

The correct answer is 3. Statement I true, Statement II false. The basement membrane provides support and anchorage to epithelial cells. However, epithelial tissues are avascular and rely on diffusion for nutrient exchange from capillaries of underlying connective tissue.

Chapter: Structural Organisation in Animals; Topic: Animal Tissues; Subtopic: Skeletal Connective Tissue – Bone and Cartilage

Keyword Definitions:

• Bone: A hard connective tissue forming the endoskeleton of vertebrates, composed of cells, fibers, and mineralized matrix.

• Ground Substance: Amorphous material in connective tissue providing support and resisting compression.

• Bone Marrow: Soft tissue inside bones responsible for producing blood cells.

• Cartilage: Semi-rigid connective tissue providing flexibility and smooth movement at joints.

• Osteocytes: Mature bone cells maintaining bone matrix.

Lead Question – (September 2024, Jhajjhar)

Statement I: The ground substance of bone is solid, pliable and resists compression.

Statement II: The bone marrow of all bones is the site of production of blood cells.

In the light of the above statements, choose the most appropriate answer from the options given below:

1. Both Statement I and Statement II are correct

2. Both Statement I and Statement II are incorrect

3. Statement I is correct but Statement II is incorrect

4. Statement I is incorrect but Statement II is correct

Explanation:

The ground substance of bone is solid and rigid due to calcium phosphate and collagen fibers, not pliable. Bone marrow is hematopoietic only in flat bones and ends of long bones, not in all bones. Therefore, both statements are incorrect. Answer: Option 2

1. Which type of connective tissue forms the framework of the human skeleton?

1. Areolar tissue

2. Bone

3. Cartilage

4. Ligament

Explanation:

Bone forms the internal supportive framework of the human body known as the endoskeleton. It protects vital organs, supports muscles, and serves as a reservoir for calcium and phosphate. It also provides attachment sites for muscles aiding locomotion. Answer: Option 2

2. The organic matrix of bone is mainly composed of:

1. Calcium phosphate

2. Collagen fibers

3. Chondrin

4. Elastin

Explanation:

The organic matrix of bone is primarily composed of collagen fibers that provide tensile strength and flexibility. Collagen works with inorganic salts like calcium phosphate to give bone its rigidity and durability. This combination ensures bones are both strong and slightly elastic. Answer: Option 2

3. Assertion-Reason Type:

Assertion (A): Bone is a highly vascular connective tissue.

Reason (R): It contains a network of canaliculi for nutrient and waste exchange between osteocytes.

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

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

3. A is true but R is false.

4. A is false but R is true.

Explanation:

Bone is a vascular tissue containing blood vessels and canaliculi that connect lacunae with osteocytes for exchange of nutrients and waste. The canaliculi help maintain the viability of bone cells, confirming that both assertion and reason are true, and R correctly explains A. Answer: Option 1

4. Fill in the Blanks:

The mineral salts that harden the bone matrix are mainly ________.

1. Calcium carbonate and magnesium sulfate

2. Calcium phosphate and calcium carbonate

3. Potassium chloride and calcium phosphate

4. Sodium sulfate and calcium carbonate

Explanation:

Bone hardness results from mineral salts like calcium phosphate and calcium carbonate deposited within the matrix. These salts combine with collagen fibers to give bones their rigidity and strength, enabling them to resist compression and support body weight. Answer: Option 2

5. Match the following:

List I List II

A. Osteoblast I. Mature bone cell

B. Osteocyte II. Bone-forming cell

C. Osteoclast III. Bone-resorbing cell

1. A-II, B-I, C-III

2. A-III, B-II, C-I

3. A-I, B-II, C-III

4. A-II, B-III, C-I

Explanation:

Osteoblasts form bone, osteocytes are mature bone cells residing in lacunae, and osteoclasts break down bone tissue during remodeling. These coordinated activities maintain bone strength and mineral balance. Correct matching is A-II, B-I, C-III. Answer: Option 1

6. Which of the following bones contains red bone marrow in adults?

1. Femur shaft

2. Humerus shaft

3. Sternum

4. Metacarpals

Explanation:

In adults, active red bone marrow is found in flat bones like sternum, ribs, vertebrae, and pelvic bones. Long bone shafts contain yellow marrow mainly for fat storage. Thus, the sternum retains hematopoietic activity. Answer: Option 3

7. The ground substance of cartilage is composed of:

1. Calcium phosphate

2. Chondrin

3. Keratin

4. Elastin

Explanation:

Cartilage has a firm and elastic ground substance called chondrin, composed of mucopolysaccharides and proteins. It provides flexibility, smoothens joint surfaces, and supports soft tissues like the nose, ear, and trachea. Answer: Option 2

8. Choose the correct statements:

Statement I: Cartilage is vascular and calcified.

Statement II: Bone is rigid and vascular.

1. Only Statement I is correct

2. Only Statement II is correct

3. Both Statements are correct

4. Both Statements are incorrect

Explanation:

Cartilage is avascular and flexible, whereas bone is highly vascular and rigid due to calcium deposition. Therefore, only Statement II is correct. Answer: Option 2

9. Which of the following cells are responsible for bone resorption?

1. Osteocytes

2. Osteoblasts

3. Osteoclasts

4. Chondrocytes

Explanation:

Osteoclasts are multinucleated giant cells responsible for resorbing or breaking down bone tissue. They release enzymes and acids that dissolve mineral salts and collagen, allowing bone remodeling and calcium homeostasis. Answer: Option 3

10. Which part of a long bone contains yellow bone marrow?

1. Diaphysis

2. Epiphysis

3. Periosteum

4. Endosteum

Explanation:

The central cavity of the diaphysis in long bones contains yellow bone marrow composed mainly of fat cells. It serves as an energy reserve and can revert to red marrow during extreme blood loss. Answer: Option 1

NEET UG Biology 2024

Chapter: Structural Organisation in Animals; Topic: Animal Tissues; Subtopic: Glandular Epithelium

Keyword Definitions:
• Glandular epithelium: Epithelium specialized for secretion.
• Unicellular gland: Single secretory cell like goblet cell.
• Multicellular gland: Cluster of cells forming a gland.
• Compound epithelium: Several layers offering protection.
• Endocrine gland: Ductless gland secreting hormones.
• Exocrine gland: Glands with ducts releasing secretions to surface.

Lead Question (2024):
Match List I with List II :

List I List II
A. Unicellular glandular epithelium I. Salivary glands
B. Compound epithelium II. Goblet cells of alimentary canal
C. Multicellular glandular epithelium III. Moist surface of buccal cavity
D. Endocrine glandular epithelium IV. Pituitary gland

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

Explanation (Answer: 1)
Unicellular glandular epithelium consists of goblet cells secreting mucus. Compound epithelium lines buccal cavity and provides protection. Multicellular glandular epithelium includes salivary glands that have ducts. Endocrine glands like the pituitary are ductless and secrete hormones directly into the bloodstream, maintaining internal coordination and regulation.

1. Which of the following is an example of a unicellular gland?
(1) Goblet cell
(2) Salivary gland
(3) Liver
(4) Pancreas
Explanation (Answer: 1)
A unicellular gland is represented by goblet cells found in the alimentary canal and respiratory tract. They secrete mucus that lubricates and protects the epithelial lining from mechanical damage and microbial entry, helping to maintain tissue moisture and defense in internal body surfaces efficiently.

2. Compound epithelium is mainly involved in —
(1) Secretion
(2) Absorption
(3) Protection
(4) Filtration
Explanation (Answer: 3)
Compound epithelium consists of multiple layers of cells providing protection against mechanical, chemical, and thermal stress. It lines surfaces like the buccal cavity, pharynx, and esophagus, preventing damage from friction and abrasive substances, rather than being directly involved in secretion or absorption.

3. Which of the following is a multicellular exocrine gland?
(1) Pituitary gland
(2) Thyroid gland
(3) Sweat gland
(4) Adrenal gland
Explanation (Answer: 3)
Sweat glands are multicellular exocrine glands that release sweat through ducts onto the skin surface. These glands help regulate body temperature through evaporation and assist in excretion of salts and urea. Their ducted nature distinguishes them from ductless endocrine glands like the thyroid or pituitary.

4. Which type of gland lacks ducts?
(1) Exocrine gland
(2) Endocrine gland
(3) Compound gland
(4) Mixed gland
Explanation (Answer: 2)
Endocrine glands are ductless glands that release hormones directly into the bloodstream. These hormones regulate physiological processes such as growth, metabolism, and reproduction. Examples include the pituitary, thyroid, and adrenal glands. Their secretions act as chemical messengers maintaining body homeostasis.

5. Fill in the Blank:
________ glands secrete their products through ducts to a body surface or cavity.
(1) Endocrine
(2) Exocrine
(3) Paracrine
(4) Autocrine
Explanation (Answer: 2)
Exocrine glands possess ducts that deliver secretions like enzymes, sweat, or saliva onto epithelial surfaces or into cavities. Examples include sweat glands, salivary glands, and gastric glands. They play key roles in digestion, lubrication, and thermoregulation, functioning differently from hormone-secreting ductless glands.

6. Choose the correct statement:
Statement I: Endocrine glands pour secretions directly into ducts.
Statement II: Salivary glands are exocrine in nature.
(1) Both statements true
(2) Both statements false
(3) Statement I false, Statement II true
(4) Statement I true, Statement II false
Explanation (Answer: 3)
Endocrine glands lack ducts and release hormones into the bloodstream, hence Statement I is false. Salivary glands have ducts that carry saliva to the oral cavity, so Statement II is correct. This distinction helps classify glands as ductless (endocrine) and ducted (exocrine).

7. Assertion–Reason:
Assertion (A): Goblet cells are glandular epithelial cells.
Reason (R): They secrete mucus to lubricate epithelial surfaces.
(1) A and R true, R correct explanation of A
(2) A and R true, R not correct explanation of A
(3) A true, R false
(4) A false, R true
Explanation (Answer: 1)
Both Assertion and Reason are true, and the Reason correctly explains the Assertion. Goblet cells are unicellular glands that secrete mucus to keep epithelial surfaces moist, facilitating the smooth passage of materials and providing a protective barrier against irritants and microbes.

8. Matching Type:
Match the following:
A. Sweat gland — I. Exocrine
B. Thyroid gland — II. Endocrine
C. Goblet cell — III. Unicellular
D. Salivary gland — IV. Compound gland
Choose the correct combination:
(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-IV, C-III, D-II
Explanation (Answer: 1)
Sweat glands are exocrine with ducts. Thyroid is an endocrine gland secreting hormones. Goblet cells are unicellular glands secreting mucus. Salivary glands are compound exocrine glands with branched ducts. Each type demonstrates structural and functional variations in glandular tissue across organ systems.

9. Which epithelium lines the moist buccal cavity?
(1) Ciliated epithelium
(2) Compound epithelium
(3) Columnar epithelium
(4) Cuboidal epithelium
Explanation (Answer: 2)
The buccal cavity is lined by compound epithelium composed of several cell layers providing protection against mechanical stress. It prevents desiccation and injury during mastication and speech. Such multilayered arrangement enables efficient protection but not secretion or absorption like simple epithelial types.

10. Which gland secretes both enzymes and hormones?
(1) Pituitary
(2) Pancreas
(3) Adrenal
(4) Thyroid
Explanation (Answer: 2)
The pancreas acts as a mixed gland. Its exocrine portion secretes digestive enzymes through ducts, while its endocrine portion releases hormones like insulin and glucagon directly into blood. This dual role enables it to participate in digestion and glucose homeostasis simultaneously within the body.

NEET UG Biology 2023 (Manipur)

Topic: Epithelial Tissue; Subtopic: Types and Locations of Epithelium

Keyword Definitions:

Epithelium: Tissue that covers body surfaces, lines cavities, and forms glands.
Columnar Epithelium: Tall, column-shaped cells specialized for absorption and secretion.
Ciliated Epithelium: Cells with hair-like structures (cilia) that move mucus or particles.
Squamous Epithelium: Flat, thin cells lining surfaces such as blood vessels and body cavities.
Cuboidal Epithelium: Cube-shaped cells typically found in ducts and secretory portions of glands.
Ducts of Glands: Tubular structures that carry secretions from glands to specific sites.
Inner Lining of Stomach and Intestine: Columnar epithelium lining the digestive tract for nutrient absorption and secretion.
Bronchioles: Small airways in lungs lined with ciliated epithelium to move mucus.
Endothelium: Squamous epithelium lining blood vessels and heart for smooth circulation.
Absorption: Process of taking in nutrients or substances by cells.
Secretion: Production and release of substances by glandular epithelial cells.

Lead Question - 2023 (Manipur):

Match List - I with List - II:
List-I List-II
(A) Columnar epithelium (I) Ducts of glands
(B) Ciliated epithelium (II) Inner lining of stomach and intestine
(C) Squamous epithelium (III) Inner lining of bronchioles
(D) Cuboidal epithelium (IV) Endothelium

Choose the correct answer from the options below:
1. III II I IV
2. III II IV I
3. II III I IV
4. II III IV I

Explanation: Correct answer is option 4: II, III, IV, I. Columnar epithelium (A) lines the inner stomach and intestine (II) for absorption and secretion. Ciliated epithelium (B) is present in bronchioles (III) to move mucus. Squamous epithelium (C) forms endothelium (IV) lining blood vessels. Cuboidal epithelium (D) is found in ducts of glands (I) for secretion. This mapping highlights the correlation between epithelial cell types, their specialized shapes, and functional roles. Understanding these structural and functional differences is critical in anatomy, histology, and physiological processes within human organs.

Guessed MCQs:

1. Single Correct Answer MCQ: Columnar epithelium is mainly found in:
(A) Skin surface
(B) Inner lining of stomach and intestine
(C) Lining of blood vessels
(D) Ducts of sweat glands
Explanation: Correct answer is (B). Columnar epithelium is tall and rectangular, lining the stomach and intestine for absorption and secretion. Skin has stratified squamous epithelium, blood vessels have squamous endothelium, and ducts have cuboidal epithelium. This illustrates how structure is specialized for physiological function.

2. Single Correct Answer MCQ: Ciliated epithelium helps in:
(A) Absorption in intestine
(B) Moving mucus in bronchioles
(C) Lining gland ducts
(D) Reducing friction in blood vessels
Explanation: Correct answer is (B). Ciliated epithelium lines bronchioles, moving mucus and trapped particles toward the throat, clearing airways. Columnar epithelium absorbs, cuboidal secretes, and squamous reduces friction, showing functional specialization of epithelial cells based on location.

3. Single Correct Answer MCQ: Squamous epithelium forms:
(A) Lining of bronchioles
(B) Inner lining of stomach
(C) Endothelium of blood vessels
(D) Ducts of glands
Explanation: Correct answer is (C). Squamous epithelium forms the endothelium lining blood vessels and heart, providing smooth surface for blood flow. Bronchioles have ciliated, stomach has columnar, ducts have cuboidal. Cell shape corresponds to functional requirements, ensuring efficient tissue performance.

4. Single Correct Answer MCQ: Cuboidal epithelium is found in:
(A) Skin
(B) Stomach lining
(C) Gland ducts
(D) Bronchioles
Explanation: Correct answer is (C). Cuboidal epithelium, cube-shaped, lines ducts of glands aiding in secretion and transport. Skin has stratified squamous, stomach has columnar, bronchioles have ciliated epithelium. Functional anatomy correlates with structure to perform specialized physiological roles.

5. Single Correct Answer MCQ: Epithelium specialized for absorption is:
(A) Squamous
(B) Columnar
(C) Cuboidal
(D) Ciliated
Explanation: Correct answer is (B). Columnar epithelium absorbs nutrients in intestine and secretes digestive enzymes in stomach. Squamous is protective, cuboidal is secretory, ciliated moves mucus. Morphology directly links to physiological role, demonstrating tissue specialization.

6. Single Correct Answer MCQ: Cilia are present on:
(A) Columnar epithelium in intestine
(B) Squamous epithelium in vessels
(C) Ciliated epithelium in bronchioles
(D) Cuboidal epithelium in ducts
Explanation: Correct answer is (C). Cilia on epithelial cells in bronchioles move mucus, aiding in respiratory clearance. Columnar absorbs, squamous protects, cuboidal secretes. Cilia demonstrate functional adaptation based on tissue location.

7. Assertion-Reason MCQ:
Assertion (A): Ciliated epithelium helps in clearing respiratory tract.
Reason (R): Cilia beat to move mucus with trapped particles.
(A) Both A and R are true, and R is correct explanation of A
(B) Both A and R are true, but R is not correct explanation of A
(C) A is true, R is false
(D) A is false, R is true
Explanation: Correct answer is (A). Cilia in respiratory epithelium beat rhythmically, moving mucus and trapped dust/pathogens, clearing airways. Functional adaptation matches structural specialization, vital for respiratory health.

8. Matching Type MCQ: Match epithelium with location:
1. Columnar A. Stomach lining
2. Ciliated B. Bronchioles
3. Squamous C. Blood vessels
4. Cuboidal D. Gland ducts
(A) 1-A, 2-B, 3-C, 4-D
(B) 1-B, 2-A, 3-D, 4-C
(C) 1-C, 2-D, 3-A, 4-B
(D) 1-D, 2-C, 3-B, 4-A
Explanation: Correct answer is (A). Columnar lines stomach/intestine, ciliated lines bronchioles, squamous forms endothelium, cuboidal is in ducts. Structure-function relationship illustrates tissue specialization in human organs.

9. Fill in the Blanks / Completion MCQ: The inner lining of bronchioles is ______ epithelium.
(A) Columnar
(B) Ciliated
(C) Squamous
(D) Cuboidal
Explanation: Correct answer is (B). Bronchioles are lined with ciliated epithelium to move mucus and debris. Columnar absorbs, squamous protects, cuboidal secretes. This demonstrates adaptation of epithelial cell type to organ function.

10. Choose the correct statements MCQ:
Statement I: Columnar epithelium lines stomach and intestine.
Statement II: Squamous epithelium forms endothelium in vessels.
(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). Columnar epithelium absorbs and secretes in digestive tract, squamous epithelium forms endothelium lining blood vessels, demonstrating how cell shape correlates with specific tissue functions, important for anatomy and histology understanding.

NEET UG Biology 2023

Chapter: Structural Organisation in Animals; Topic: Animal Tissues; Subtopic: Epithelial and Connective Tissues

Keyword Definitions:
• Epithelial Tissue: Tissue covering external and internal surfaces, forming protective layers and involved in secretion and absorption.
• Connective Tissue: Tissue that connects, supports, and binds other tissues; includes blood, cartilage, and areolar tissue.
• Mast Cells: Immune cells found in connective tissue that release histamine, heparin, and serotonin during inflammation.
• Nephron: Structural and functional unit of the kidney responsible for filtration and urine formation.
• Bronchiole: Narrow air passage in lungs lined by ciliated epithelium that helps remove mucus and dust.

Lead Question (2023):
Match List I with List II
List I List II
A. Mast cells I. Ciliated epithelium
B. Inner surface of bronchiole II. Areolar tissue
C. Blood III. Cuboidal epithelium
D. Tubular parts of nephron IV. Specialised tissue

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

Explanation (Answer: 1)
Mast cells are found in areolar connective tissue where they secrete histamine and heparin. The inner surface of bronchioles is lined by ciliated epithelium that helps remove dust particles. Blood is a specialised connective tissue for transport, and the tubular parts of nephrons are lined by cuboidal epithelium aiding secretion and absorption. Correct match is (1).

1. Which of the following epithelial tissues lines the kidney tubules?
(1) Squamous epithelium
(2) Cuboidal epithelium
(3) Columnar epithelium
(4) Ciliated epithelium
Explanation: The kidney tubules are lined with cuboidal epithelium, which helps in selective absorption and secretion during urine formation. These cube-shaped cells have central nuclei and microvilli that increase surface area for reabsorption. Hence, the correct answer is (2) Cuboidal epithelium.

2. Which of the following is a specialised connective tissue?
(1) Areolar tissue
(2) Blood
(3) Ligament
(4) Tendon
Explanation: Blood is a specialised connective tissue as it performs transport, regulation, and protection functions. It has a liquid matrix (plasma) containing erythrocytes, leukocytes, and platelets. Unlike other connective tissues, blood lacks fibres but connects body systems by circulating nutrients and gases. Hence, the correct answer is (2).

3. Ciliated epithelium is mainly responsible for:
(1) Absorption
(2) Conduction of impulses
(3) Movement of particles
(4) Secretion of mucus
Explanation: Ciliated epithelium lines respiratory passages like trachea and bronchioles. Its coordinated beating helps move mucus and trapped particles out of the airways, protecting lungs from pathogens and dust. It also lines reproductive tracts, aiding movement of gametes. Hence, the correct answer is (3) Movement of particles.

4. Which of the following is a loose connective tissue?
(1) Cartilage
(2) Bone
(3) Areolar tissue
(4) Ligament
Explanation: Areolar tissue is a loose connective tissue found beneath epithelial layers. It binds skin to muscles, supports organs, and allows flexibility. It contains fibroblasts, mast cells, macrophages, and fibres like collagen and elastin. Hence, the correct answer is (3) Areolar tissue.

5. Mast cells secrete:
(1) Collagen and elastin
(2) Histamine, heparin and serotonin
(3) Antibodies
(4) Digestive enzymes
Explanation: Mast cells are found in connective tissues and secrete histamine (inflammatory response), heparin (anticoagulant), and serotonin (vasodilation). These substances help defend against pathogens and repair tissues. They play an essential role in allergic reactions. Hence, the correct answer is (2).

6. The lining of alveoli in lungs is composed of:
(1) Simple squamous epithelium
(2) Simple cuboidal epithelium
(3) Stratified epithelium
(4) Columnar epithelium
Explanation: The alveoli are lined by simple squamous epithelium which allows efficient diffusion of gases between air and blood. The thin, flat cells minimise diffusion distance and facilitate oxygen uptake and CO₂ removal. Hence, the correct answer is (1) Simple squamous epithelium.

7. Assertion-Reason Type:
Assertion (A): Blood is considered a connective tissue.
Reason (R): It connects different body systems by transporting materials.
(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: Blood is a connective tissue as it originates from mesoderm and connects various organs by transporting nutrients, gases, and hormones. Hence, both A and R are true, and R correctly explains A. Correct answer: (1).

8. Matching Type:
Match List I with List II:
A. Cartilage I. Chondrocytes
B. Bone II. Osteocytes
C. Areolar tissue III. Fibroblasts
(1) A-I, B-II, C-III
(2) A-II, B-I, C-III
(3) A-III, B-II, C-I
(4) A-I, B-III, C-II
Explanation: Cartilage contains chondrocytes in lacunae, bone contains osteocytes embedded in matrix, and areolar tissue has fibroblasts producing fibres. Each tissue has distinct structure and function, providing support and flexibility. Correct match is (1) A-I, B-II, C-III.

9. Fill in the Blanks:
The functional unit of the kidney responsible for filtration and urine formation is called ________.
(1) Neuron
(2) Nephron
(3) Glomerulus
(4) Bowman’s capsule
Explanation: Nephron is the structural and functional unit of the kidney. It consists of the glomerulus and tubules that filter blood, reabsorb essential substances, and form urine. The process maintains water and electrolyte balance. Hence, the correct answer is (2) Nephron.

10. Choose the correct statements:
Statement I: Ciliated epithelium helps in the movement of mucus in respiratory passages.
Statement II: Mast cells play a key role in allergic responses.
(1) Both statements are true.
(2) Both statements are false.
(3) Only Statement I is true.
(4) Only Statement II is true.
Explanation: The cilia on epithelial cells move mucus and trapped particles, cleaning respiratory passages. Mast cells secrete histamine and cause allergic reactions, swelling, and inflammation. Both statements are correct. Correct answer: (1).

Topic: Connective Tissues; Subtopic: Ligaments and Cartilage Structure

Lead Question - 2023

Given below are two statements:
Statement I: Ligaments are dense irregular tissue.
Statement II: Cartilage is dense regular tissue.
In the light of the above statements, choose the correct answer from the options given below:
(1) Statement I is true but Statement II is false
(2) Statement I is false but Statement II is true
(3) Both Statement I and Statement II are true
(4) Both Statement I and Statement II are false

Answer: (1) Statement I is true but Statement II is false. Ligaments are composed of dense irregular connective tissue, providing strength and flexibility in multiple directions to stabilize joints. Cartilage is not dense regular tissue; it is a specialized connective tissue with chondrocytes embedded in a matrix, providing support and cushioning. Unlike dense regular tissue, cartilage does not have fibers arranged in parallel bundles. Hence, Statement I is correct, and Statement II is incorrect.

Keyword Definitions:

Ligament: A fibrous connective tissue connecting bones to other bones, providing joint stability.
Dense Irregular Tissue: Connective tissue with collagen fibers arranged irregularly to withstand stresses from multiple directions.
Cartilage: Specialized connective tissue with chondrocytes in a firm, flexible matrix for support and cushioning.
Dense Regular Tissue: Connective tissue with parallel collagen fibers, providing strength in one direction, typical of tendons.
Chondrocytes: Cells found in cartilage responsible for producing and maintaining the matrix.
Connective Tissue: Tissue that supports, connects, or separates different types of tissues and organs in the body.
Joint: A structure that connects bones and allows for movement and mechanical support.

Guessed MCQs based on Lead Question:

1. Single Correct Answer:

Which connective tissue connects bone to bone and stabilizes joints?
(1) Tendon
(2) Ligament
(3) Cartilage
(4) Adipose tissue

Answer: (2) Ligament. Ligaments are dense irregular connective tissues connecting bones to bones, providing joint stability and limiting excessive movement. Their irregular collagen fiber arrangement allows flexibility and resistance to stresses from multiple directions, crucial for joint integrity.

2. Single Correct Answer:

Which tissue has parallel collagen fibers and connects muscles to bones?
(1) Ligament
(2) Cartilage
(3) Tendon
(4) Areolar tissue

Answer: (3) Tendon. Tendons are dense regular connective tissues with collagen fibers arranged in parallel bundles. This organization provides tensile strength along a single direction, enabling efficient transmission of muscle contraction forces to bones for movement.

3. Single Correct Answer:

Cartilage is primarily composed of:
(1) Fibroblasts
(2) Chondrocytes
(3) Osteocytes
(4) Adipocytes

Answer: (2) Chondrocytes. Cartilage contains chondrocytes embedded in a firm extracellular matrix composed of collagen and proteoglycans. These cells maintain the matrix, ensuring structural support and cushioning in joints and other connective tissue locations.

4. Single Correct Answer:

Which connective tissue provides support, flexibility, and cushioning in joints?
(1) Dense regular tissue
(2) Cartilage
(3) Ligament
(4) Elastic tissue

Answer: (2) Cartilage. Cartilage is a specialized connective tissue with a semi-rigid matrix, providing support, flexibility, and cushioning at joints. It prevents bone-to-bone friction, maintains shape in structures like the ear and nose, and absorbs mechanical stress during movement.

5. Single Correct Answer:

Which connective tissue resists stress from multiple directions due to irregular fiber arrangement?
(1) Dense regular tissue
(2) Dense irregular tissue
(3) Cartilage
(4) Adipose tissue

Answer: (2) Dense irregular tissue. Dense irregular connective tissue has collagen fibers arranged randomly, enabling it to withstand stress from multiple directions. Ligaments are an example, providing joint stability while allowing flexibility in various planes.

6. Single Correct Answer:

Tendons differ from ligaments because:
(1) Tendons connect bones to bones
(2) Tendons are dense irregular tissue
(3) Tendons connect muscles to bones and are dense regular tissue
(4) Tendons are composed of cartilage

Answer: (3) Tendons connect muscles to bones and are dense regular tissue. Unlike ligaments, which are dense irregular and connect bone to bone, tendons transmit muscle contraction forces to bones efficiently due to parallel collagen fibers.

7. Assertion-Reason:

Assertion A: Ligaments are dense irregular connective tissue.
Reason R: Their irregular fiber arrangement provides strength in multiple directions.
(1) A is true but R is false
(2) A is false but R is true
(3) Both A and R are true and R explains A
(4) Both A and R are true but R does not explain A

Answer: (3) Both A and R are true and R explains A. Ligaments are dense irregular connective tissues, and their randomly arranged collagen fibers provide tensile strength in multiple directions, which is crucial for stabilizing joints and resisting multidirectional stresses.

8. Matching Type:

Match connective tissue with its correct property:
List I | List II
A. Ligament | I. Dense regular, connects muscle to bone
B. Tendon | II. Dense irregular, connects bone to bone
C. Cartilage | III. Chondrocytes, semi-rigid matrix
D. Elastic tissue | IV. Stretchable, found in arteries
(1) A-II, B-I, C-III, D-IV
(2) A-I, B-II, C-III, D-IV
(3) A-III, B-IV, C-II, D-I
(4) A-IV, B-III, C-I, D-II

Answer: (1) A-II, B-I, C-III, D-IV. Ligaments are dense irregular tissue connecting bones, tendons are dense regular connecting muscles to bones, cartilage contains chondrocytes in semi-rigid matrix, and elastic tissue is stretchable, found in arteries.

9. Fill in the Blanks:

_________ connects bones to bones and is dense irregular, whereas _________ connects muscles to bones and is dense regular.
(1) Ligament; Tendon
(2) Tendon; Ligament
(3) Cartilage; Ligament
(4) Elastic tissue; Cartilage

Answer: (1) Ligament; Tendon. Ligaments connect bones to bones and are composed of dense irregular connective tissue, providing multidirectional strength. Tendons connect muscles to bones and are dense regular connective tissue, transmitting unidirectional forces effectively.

10. Choose the Correct Statements:

Statement I: Cartilage cells are called chondrocytes.
Statement II: Ligaments are dense regular connective tissue.
(1) Only Statement I is correct
(2) Only Statement II is correct
(3) Both statements are correct
(4) Both statements are incorrect

Answer: (1) Only Statement I is correct. Cartilage contains chondrocytes which maintain its matrix. Ligaments are dense irregular connective tissue, not dense regular. Therefore, Statement I is true, and Statement II is false.

Subtopic: Types of Muscular Tissue

Keyword Definitions:
• Skeletal Muscle Fibres: Long, cylindrical, multinucleated cells responsible for voluntary movements.
• Cardiac Muscle: Involuntary, striated muscle found in heart; possesses intercalated discs for coordinated contraction.
• Intercalated Discs: Specialized junctions in cardiac muscle that allow rapid electrical and mechanical coupling between cells.
• Smooth Muscle: Involuntary, non-striated muscle found in walls of hollow organs and blood vessels.
• Muscular Tissue: Tissue type specialized for contraction to produce movement.

Lead Question - 2022 (Ganganagar)

Choose the correct statement about a muscular tissue:

1. Skeletal muscle fibres are uninucleated and found in parallel bundles.
2. Intercalated discs allow the cardiac muscle cells to contract as a unit.
3. The walls of blood vessels are made up of columnar epithelium.
4. Smooth muscles are multinucleated and involuntary.

Explanation: The correct answer is option 2. Intercalated discs in cardiac muscle are specialized junctions containing gap junctions and desmosomes. They allow rapid transmission of electrical impulses and mechanical coordination, enabling cardiac cells to contract as a functional syncytium. Skeletal muscles are multinucleated and voluntary; smooth muscles are uninucleated and involuntary; blood vessel walls are lined by endothelial cells, not columnar epithelium. Intercalated discs are unique to cardiac muscle and crucial for synchronized heartbeat and efficient pumping of blood throughout the body.

1. Which type of muscle is voluntary and striated?
1. Skeletal muscle
2. Cardiac muscle
3. Smooth muscle
4. None of the above

Explanation: The correct answer is skeletal muscle. Skeletal muscles are voluntary, striated, and multinucleated. They attach to bones and are responsible for body movements under conscious control. Cardiac muscles are striated but involuntary; smooth muscles are non-striated and involuntary. Skeletal muscles contract rapidly and fatigue over time.

2. Smooth muscles are found in:
1. Heart
2. Skeletal limbs
3. Walls of hollow organs
4. Skin

Explanation: The correct answer is walls of hollow organs. Smooth muscles are involuntary, non-striated, and found in the walls of intestines, stomach, blood vessels, and bladder. They regulate the movement of substances through organs by slow, sustained contractions. Skeletal muscles control limb movements, cardiac muscle forms the heart, and skin contains muscles like arrector pili.

3. Which structural feature allows cardiac muscle to function as a syncytium?
1. Sarcomere
2. Intercalated discs
3. T-tubules
4. Myofibrils

Explanation: The correct answer is intercalated discs. Intercalated discs contain gap junctions and desmosomes that enable rapid electrical communication and mechanical linkage among cardiac cells. This allows all cardiac cells to contract in a coordinated manner, functioning as a syncytium, which is critical for effective pumping of blood.

4. Which statement is true about skeletal muscle fibres?
1. They are uninucleated
2. They are multinucleated
3. They have intercalated discs
4. They are non-striated

Explanation: The correct answer is multinucleated. Skeletal muscle fibres are long, cylindrical, multinucleated cells with striations. They lack intercalated discs, which are exclusive to cardiac muscle. Multinucleation allows efficient synthesis of proteins and enzymes needed for contraction and repair.

5. The primary function of smooth muscle is:
1. Voluntary movement of limbs
2. Pumping blood
3. Involuntary movement of internal organs
4. Maintaining posture

Explanation: The correct answer is involuntary movement of internal organs. Smooth muscles contract slowly and rhythmically to move food, blood, and waste through hollow organs. They operate without conscious control and regulate processes such as peristalsis, vasoconstriction, and bladder emptying.

6. Cardiac muscle is characterized by:
1. Voluntary control
2. Presence of intercalated discs
3. Non-striated fibres
4. Multinucleated fibres

Explanation: The correct answer is presence of intercalated discs. Cardiac muscle is involuntary, striated, and mostly uninucleated. Intercalated discs facilitate synchronized contraction, allowing efficient pumping. Voluntary control is a feature of skeletal muscles; non-striated and multinucleated traits are associated with smooth and skeletal muscles, respectively.

7. Assertion-Reason Question:
Assertion (A): Intercalated discs are essential for coordinated cardiac contraction.
Reason (R): They contain gap junctions for electrical coupling and desmosomes for mechanical stability.

1. Both A and R are true, and R is correct explanation for A
2. Both A and R are true, but R is not correct explanation for A
3. A true, R false
4. A false, R true

Explanation: The correct answer is option 1. Intercalated discs allow electrical impulses to spread quickly through cardiac tissue and provide mechanical strength via desmosomes. This ensures all cardiac cells contract as a unit, coordinating heartbeat efficiently.

8. Matching Type:
Match the type of muscle with characteristic:
(a) Skeletal - (i) Striated, voluntary
(b) Cardiac - (ii) Striated, involuntary, intercalated discs
(c) Smooth - (iii) Non-striated, involuntary

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)-(ii), (c)-(i)

Explanation: The correct answer is option 1. Skeletal muscle is striated and voluntary, cardiac muscle is striated, involuntary, and contains intercalated discs, while smooth muscle is non-striated and involuntary. This classification is based on structure and control mechanism.

9. Fill in the Blanks:
The walls of the heart are made up of ________ muscle tissue.

1. Skeletal
2. Smooth
3. Cardiac
4. Connective

Explanation: The correct answer is cardiac muscle. Cardiac muscle is specialized, striated, involuntary muscle that forms the myocardium of the heart. It contains intercalated discs, allowing synchronized contraction and efficient pumping of blood throughout the circulatory system.

10. Choose the Correct Statements:
Statement I: Smooth muscles lack striations and are involuntary.
Statement II: Skeletal muscles contain intercalated discs.

1. Only Statement I correct
2. Only Statement II correct
3. Both I and II correct
4. Both I and II incorrect

Explanation: The correct answer is option 1. Smooth muscles are non-striated and operate involuntarily in hollow organs. Skeletal muscles are striated, multinucleated, and voluntary, and do not contain intercalated discs; those are unique to cardiac muscle.

Chapter: Animal Tissue; Topic: Epithelial Tissue; Subtopic: Ciliated Epithelium

Keyword Definitions:

• Epithelium: Tissue that covers body surfaces, lines cavities and ducts, and forms glands.

• Bronchioles: Small air passages in the lungs connecting bronchi to alveoli.

• Fallopian tubes: Female reproductive tubes connecting ovaries to the uterus.

• Ciliated epithelium: Columnar cells with hair-like cilia on apical surface for movement of substances.

• Simple squamous epithelium: Single layer of flat cells, facilitates diffusion.

• Simple columnar epithelium: Single layer of tall cells, absorption and secretion.

• Stratified squamous epithelium: Multiple layers of flat cells, protection from abrasion.

• Cilia: Motile projections that move fluids or particles over epithelial surfaces.

• Mucus: Sticky secretion produced by goblet cells in ciliated epithelium.

• Respiratory epithelium: Epithelium lining airways, often ciliated and mucus-secreting.

• Transport function: Movement of ova in Fallopian tubes or mucus in bronchioles.

Lead Question - 2022 (Ganganagar)

Which of the following types of epithelium is present in the bronchioles and Fallopian tubes?

1. Simple squamous epithelium

2. Simple columnar epithelium

3. Ciliated epithelium

4. Stratified squamous epithelium

Explanation: The bronchioles and Fallopian tubes are lined by ciliated epithelium. The cilia help move mucus in bronchioles and ova in Fallopian tubes. Simple squamous is for diffusion, simple columnar mainly for absorption/secretion, and stratified squamous for protection. Therefore, ciliated epithelium is specialized for transport of materials along the epithelial surface. Correct answer is 3.

1. Single Correct Answer MCQ:

Which cells in ciliated epithelium secrete mucus?

a) Goblet cells

b) Squamous cells

c) Columnar cells without cilia

d) Basal cells

Explanation: Goblet cells present among ciliated epithelial cells secrete mucus, which traps dust and microbes in bronchioles. This helps cilia move the mucus efficiently. Correct answer is a.

2. Single Correct Answer MCQ:

Cilia in epithelial tissue are primarily responsible for:

a) Absorption of nutrients

b) Protection against abrasion

c) Movement of particles or fluids

d) Secretion of enzymes

Explanation: Cilia are motile projections that move fluids, mucus, or cells along the epithelial surface. In bronchioles, they clear mucus; in Fallopian tubes, they move the ovum. Correct answer is c.

3. Single Correct Answer MCQ:

Which type of epithelium forms the alveolar walls for gas exchange?

a) Simple squamous

b) Ciliated epithelium

c) Stratified squamous

d) Simple columnar

Explanation: Simple squamous epithelium is thin and flat, ideal for rapid diffusion of oxygen and carbon dioxide in alveoli. Correct answer is a.

4. Single Correct Answer MCQ:

The main function of stratified squamous epithelium is:

a) Secretion

b) Absorption

c) Protection

d) Transport

Explanation: Stratified squamous epithelium has multiple layers to protect underlying tissues from abrasion and injury. Found in skin, oral cavity, and esophagus. Correct answer is c.

5. Single Correct Answer MCQ:

Which epithelium type lines the gastrointestinal tract for absorption?

a) Simple squamous

b) Simple columnar

c) Ciliated epithelium

d) Stratified squamous

Explanation: Simple columnar epithelium forms the lining of the intestine, specialized for absorption and secretion. Correct answer is b.

6. Single Correct Answer MCQ:

Where is ciliated epithelium found in the female reproductive system?

a) Vagina

b) Fallopian tubes

c) Ovary surface

d) Cervical canal

Explanation: Ciliated epithelium lines the Fallopian tubes and helps in transporting the ovum from ovary to uterus. Correct answer is b.

7. Assertion-Reason MCQ:

Assertion (A): Ciliated epithelium is present in bronchioles and Fallopian tubes.

Reason (R): Cilia help in transport of particles in bronchioles and ova in Fallopian tubes.

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 assertion and reason are true; the presence of cilia explains the transport function. Correct answer is a.

8. Matching Type MCQ:

Match List-I with List-II:

List-I | List-II

(a) Bronchioles | (i) Protection

(b) Fallopian tubes | (ii) Transport of ovum

(c) Skin | (iii) Transport of mucus

(d) Alveoli | (iv) Diffusion of gases

Options:

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

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

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

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

Explanation: Bronchioles (ciliated, mucus transport), Fallopian tubes (transport ovum), Skin (protection), Alveoli (gas diffusion). Correct answer is 1.

9. Fill in the Blanks / Completion MCQ:

The hair-like projections in epithelial cells that move mucus or ovum are called ________.

a) Microvilli

b) Cilia

c) Flagella

d) Villi

Explanation: Cilia are motile projections on epithelial cells that help in transport of mucus in bronchioles and ovum in Fallopian tubes. Correct answer is b.

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

Statement I: Ciliated epithelium is present in bronchioles and Fallopian tubes.

Statement II: Cilia help in movement of mucus and ovum.

a) Both I and II correct

b) Only I correct

c) Only II correct

d) Both incorrect

Explanation: Both statements are correct. Ciliated epithelium lines bronchioles and Fallopian tubes, and cilia help transport mucus and ova. Correct answer is a.