Tissue = group of similar cells specialized to perform a specific function. AMU asks 2–3 MCQs — focus on meristematic vs permanent tissues, simple vs complex tissues, epithelial tissue types, connective tissue subtypes, and muscular tissue types.
1) Plant tissues
Two major categories:
• Meristematic tissues — actively dividing cells (growth).
• Permanent tissues — mature, differentiated cells (specialized functions).
• Meristematic tissues — actively dividing cells (growth).
• Permanent tissues — mature, differentiated cells (specialized functions).
1.1 Meristematic tissues
| Type | Location | Function |
|---|---|---|
| Apical meristem | Root & shoot tips | Primary growth (length increase) |
| Lateral meristem (Cambium) | Vascular bundles (between xylem & phloem); cork cambium | Secondary growth (girth/thickness increase) |
| Intercalary meristem | Base of leaves/internodes (in grasses) | Rapid regeneration after grazing/cutting |
• Cells: small, thin-walled, dense cytoplasm, large nucleus, no vacuoles, tightly packed.
• Primary meristem (derived directly from embryo) vs Secondary meristem (arises later in mature tissues).
• Primary meristem (derived directly from embryo) vs Secondary meristem (arises later in mature tissues).
1.2 Simple permanent tissues
| Tissue | Cell wall | Living/Dead at maturity | Function | Location |
|---|---|---|---|---|
| Parenchyma | Thin (cellulose) | Living | Storage, photosynthesis (cholenchyma — with chloroplasts), packing | All plant parts (cortex, pith, mesophyll) |
| Collenchyma | Unevenly thickened (pectin + cellulose) | Living | Flexible mechanical support in growing stems/leaves | Hypodermis of dicot stems, leaf petioles |
| Sclerenchyma | Very thick (lignin) | Dead | Rigid mechanical support | Seed coat, stem vascular bundle sheath, fruit walls |
• Fibers (long, pointed — used in ropes) and Sclereids (short, irregular — give gritty texture to pear/guava) are types of sclerenchyma.
• Epidermis: Protective outer layer, covered by cuticle (waxy → prevents water loss). In roots, epidermal cells form root hairs (increase absorption). Stomata (guard cells + pore) for gas exchange.
• Epidermis: Protective outer layer, covered by cuticle (waxy → prevents water loss). In roots, epidermal cells form root hairs (increase absorption). Stomata (guard cells + pore) for gas exchange.
Fig: Simple & complex plant tissues
1.3 Complex permanent tissues — Vascular tissues
| Feature | Xylem | Phloem |
|---|---|---|
| Function | Water & mineral transport (root → shoot) | Food transport (source → sink) |
| Direction | Unidirectional (upward only) | Bidirectional (up/down based on need) |
| Components | Tracheids, Vessels, Xylem fibres, Xylem parenchyma | Sieve tubes, Companion cells, Phloem fibres, Phloem parenchyma |
| Conducting cells | Tracheids & Vessels (dead at maturity, lignified) | Sieve tubes (living, no nucleus at maturity) |
| Support | Xylem fibres | Phloem fibres (bast fibres — jute, flax) |
| Living cells in tissue | Xylem parenchyma only | Sieve tubes, Companion cells, Phloem parenchyma |
🔥 AMU PYQ: Which of the following plant tissues provides flexible support?
(A) Parenchyma (B) Collenchyma (C) Sclerenchyma (D) Xylem
Ans: B (Collenchyma — unevenly thickened, living, provides flexible support)
(A) Parenchyma (B) Collenchyma (C) Sclerenchyma (D) Xylem
Ans: B (Collenchyma — unevenly thickened, living, provides flexible support)
🔥 AMU PYQ: The conducting cells of phloem are:
(A) Tracheids (B) Vessels (C) Sieve tubes (D) Fibres
Ans: C (Sieve tubes — living but lose nucleus at maturity; companion cells help them function)
(A) Tracheids (B) Vessels (C) Sieve tubes (D) Fibres
Ans: C (Sieve tubes — living but lose nucleus at maturity; companion cells help them function)
2) Animal tissues
Four basic types: Epithelial (covering), Connective (support), Muscular (movement), Nervous (control & coordination).
2.1 Epithelial tissue
• Covers body surfaces, lines cavities, forms glands.
• Basement membrane anchors epithelium to underlying tissue.
• Cells tightly packed with little intercellular space; avascular (no blood vessels — gets nutrients by diffusion).
• Basement membrane anchors epithelium to underlying tissue.
• Cells tightly packed with little intercellular space; avascular (no blood vessels — gets nutrients by diffusion).
| Type | Structure | Location | Function |
|---|---|---|---|
| Squamous | Thin, flat, irregular (like tiles) | Skin outer layer, lung alveoli, blood vessel lining (endothelium) | Protection, diffusion, filtration |
| Cuboidal | Cube-shaped | Kidney tubules, salivary glands, ovary surface | Secretion, absorption |
| Columnar | Tall, pillar-like | Stomach, intestine lining; gall bladder | Secretion (mucus), absorption |
| Ciliated columnar | Columnar with cilia (hair-like projections) | Trachea, bronchi, fallopian tubes | Moves mucus/egg in specific direction |
| Glandular | Modified columnar/cuboidal forming glands | Sweat glands, salivary glands, endocrine glands | Secretion (enzymes, hormones, sweat) |
| Stratified squamous | Multiple layers of squamous cells | Outer skin, mouth lining, oesophagus | Protection against wear & tear |
| Transitional | Stretchable, multi-layered | Urinary bladder, ureter, urethra | Stretches to accommodate urine volume |
🔥 AMU PYQ: The inner lining of the trachea is made of:
(A) Squamous epithelium (B) Ciliated columnar epithelium (C) Cuboidal epithelium (D) Glandular epithelium
Ans: B (Cilia move mucus + trapped particles upward → cough out)
(A) Squamous epithelium (B) Ciliated columnar epithelium (C) Cuboidal epithelium (D) Glandular epithelium
Ans: B (Cilia move mucus + trapped particles upward → cough out)
2.2 Connective tissue
• Most abundant & widespread tissue in the body.
• Cells scattered in extracellular matrix (ground substance + protein fibres — collagen, elastin).
• Highly vascular (except cartilage) — rich blood supply.
• Cells scattered in extracellular matrix (ground substance + protein fibres — collagen, elastin).
• Highly vascular (except cartilage) — rich blood supply.
| Type | Matrix | Cells | Location | Function |
|---|---|---|---|---|
| Areolar (Loose connective) | Loose gel with collagen & elastin fibres | Fibroblasts, macrophages, mast cells | Under skin, between organs, around blood vessels | Cushion, binds organs, helps tissue repair |
| Adipose | Little matrix; packed with fat droplets | Adipocytes (fat cells) | Under skin (subcutaneous), around kidneys & heart | Fat storage, insulation, shock absorption |
| Tendons | Dense regular (collagen fibres in parallel) | Fibroblasts | Muscle → bone attachment | Transmit force (strong, flexible) |
| Ligaments | Dense regular (elastin + collagen) | Fibroblasts | Bone → bone at joints | Binds bones, allows some stretch |
| Bone | Hard (calcium phosphate + collagen) | Osteocytes (in lacunae) | Skeleton, ear ossicles | Support, protection, mineral storage, movement (via joints) |
| Cartilage | Firm gel (chondroitin + collagen) | Chondrocytes (in lacunae) | Nose, ear, trachea, joints, intervertebral discs | Flexible support, reduces friction at joints |
| Blood | Fluid (plasma — water + proteins) | RBCs, WBCs, Platelets | Blood vessels | Transport (O₂, CO₂, nutrients, hormones, wastes), immunity, clotting |
🔥 AMU PYQ: Which connective tissue stores fat in the body?
(A) Areolar (B) Adipose (C) Bone (D) Cartilage
Ans: B (Adipose tissue — adipocytes store fat for energy, insulation, cushioning)
(A) Areolar (B) Adipose (C) Bone (D) Cartilage
Ans: B (Adipose tissue — adipocytes store fat for energy, insulation, cushioning)
🔥 AMU PYQ: Tendons connect:
(A) Bone to bone (B) Muscle to bone (C) Muscle to muscle (D) Nerve to muscle
Ans: B (Tendon = muscle → bone; Ligament = bone → bone)
(A) Bone to bone (B) Muscle to bone (C) Muscle to muscle (D) Nerve to muscle
Ans: B (Tendon = muscle → bone; Ligament = bone → bone)
2.3 Muscular tissue
| Feature | Skeletal (Striated/Voluntary) | Smooth (Non-striated/Involuntary) | Cardiac (Striated/Involuntary) |
|---|---|---|---|
| Location | Attached to skeleton | Walls of internal organs — stomach, intestine, blood vessels, bladder, uterus | Heart wall (myocardium) |
| Striations | Present (alternating light/dark bands) | Absent (smooth appearance) | Present (faint) |
| Nucleus | Multinucleated (peripheral) | Single (central) | Single (central, sometimes binucleated) |
| Control | Voluntary (conscious) | Involuntary (autonomic) | Involuntary (autonomic) |
| Cell shape | Long, cylindrical, unbranched | Spindle-shaped, tapering ends | Cylindrical, branched (intercalated discs) |
| Fatigue | Yes (tires easily) | No (slow, sustained contractions) | No (works continuously) |
Fig: Skeletal, smooth, and cardiac muscle structure
🔥 AMU PYQ: The muscle that shows branched cells with intercalated discs is:
(A) Skeletal (B) Smooth (C) Cardiac (D) Voluntary
Ans: C (Cardiac muscle — intercalated discs help in synchronized contraction)
(A) Skeletal (B) Smooth (C) Cardiac (D) Voluntary
Ans: C (Cardiac muscle — intercalated discs help in synchronized contraction)
2.4 Nervous tissue
• Made of neurons (nerve cells) and neuroglial cells (supporting cells).
• Neuron structure: Dendrites (receive signals) → Cell body (nucleus + Nissl granules) → Axon (conducts impulse) → Axon terminals (release neurotransmitters at synapse).
• Myelin sheath (Schwann cells in PNS, oligodendrocytes in CNS) — insulates axon, speeds up impulse (saltatory conduction).
• Functions: Receives stimuli, transmits nerve impulses, coordinates body activities.
• Neuron structure: Dendrites (receive signals) → Cell body (nucleus + Nissl granules) → Axon (conducts impulse) → Axon terminals (release neurotransmitters at synapse).
• Myelin sheath (Schwann cells in PNS, oligodendrocytes in CNS) — insulates axon, speeds up impulse (saltatory conduction).
• Functions: Receives stimuli, transmits nerve impulses, coordinates body activities.
Types of neurons:
• Sensory (Afferent): Receptor → CNS (spinal cord/brain).
• Motor (Efferent): CNS → Effector (muscle/gland).
• Interneurons (Relay): Within CNS — connect sensory and motor neurons.
• Sensory (Afferent): Receptor → CNS (spinal cord/brain).
• Motor (Efferent): CNS → Effector (muscle/gland).
• Interneurons (Relay): Within CNS — connect sensory and motor neurons.
Fig: Structure of a typical neuron
🔥 AMU PYQ: The longest cell in the human body is:
(A) Muscle cell (B) Nerve cell (C) Bone cell (D) Skin cell
Ans: B (Neurons — some can be over 1 m long, from spinal cord to toes)
(A) Muscle cell (B) Nerve cell (C) Bone cell (D) Skin cell
Ans: B (Neurons — some can be over 1 m long, from spinal cord to toes)
3) AMU PYQs — quick revision
Q1. Meristematic tissue is found in:
(A) Root tip (B) Bark (C) Leaf (D) Fruit Ans: A
(A) Root tip (B) Bark (C) Leaf (D) Fruit Ans: A
Q2. The tissue that transports water in plants is:
(A) Phloem (B) Xylem (C) Epidermis (D) Parenchyma Ans: B
(A) Phloem (B) Xylem (C) Epidermis (D) Parenchyma Ans: B
Q3. Companion cells are associated with:
(A) Xylem vessels (B) Sieve tubes (C) Tracheids (D) Fibres Ans: B
(A) Xylem vessels (B) Sieve tubes (C) Tracheids (D) Fibres Ans: B
Q4. Which of the following is a dead tissue at maturity?
(A) Phloem (B) Collenchyma (C) Parenchyma (D) Sclerenchyma Ans: D
(A) Phloem (B) Collenchyma (C) Parenchyma (D) Sclerenchyma Ans: D
Q5. The lining of blood vessels is made of:
(A) Squamous epithelium (B) Cuboidal (C) Columnar (D) Ciliated Ans: A
(A) Squamous epithelium (B) Cuboidal (C) Columnar (D) Ciliated Ans: A
Q6. Which tissue helps in the movement of body parts?
(A) Epithelial (B) Nervous (C) Muscular (D) Connective Ans: C
(A) Epithelial (B) Nervous (C) Muscular (D) Connective Ans: C
Q7. The epithelial tissue with cilia is found in:
(A) Kidney tubules (B) Trachea (C) Oesophagus (D) Skin Ans: B
(A) Kidney tubules (B) Trachea (C) Oesophagus (D) Skin Ans: B
Q8. Intercalated discs are found in:
(A) Skeletal muscle (B) Smooth muscle (C) Cardiac muscle (D) Bone Ans: C
(A) Skeletal muscle (B) Smooth muscle (C) Cardiac muscle (D) Bone Ans: C
Q9. Which tissue stores minerals like calcium and phosphorus?
(A) Cartilage (B) Bone (C) Blood (D) Adipose Ans: B
(A) Cartilage (B) Bone (C) Blood (D) Adipose Ans: B
Q10. The fatty layer around a neuron is called:
(A) Myelin sheath (B) Neurilemma (C) Synapse (D) Dendrite Ans: A
(A) Myelin sheath (B) Neurilemma (C) Synapse (D) Dendrite Ans: A
Q11. Cork cells are impervious to water due to:
(A) Lignin (B) Suberin (C) Cutin (D) Pectin Ans: B (Suberin — in cork cambium, makes bark waterproof)
(A) Lignin (B) Suberin (C) Cutin (D) Pectin Ans: B (Suberin — in cork cambium, makes bark waterproof)
Q12. The tissue responsible for secondary growth in plants is:
(A) Apical meristem (B) Lateral meristem (C) Intercalary meristem (D) Parenchyma Ans: B
(A) Apical meristem (B) Lateral meristem (C) Intercalary meristem (D) Parenchyma Ans: B
Q13. Ligaments connect:
(A) Muscle to bone (B) Bone to bone (C) Nerve to muscle (D) Skin to muscle Ans: B
(A) Muscle to bone (B) Bone to bone (C) Nerve to muscle (D) Skin to muscle Ans: B
Q14. The matrix of blood is:
(A) Serum (B) Plasma (C) Lymph (D) Cytosol Ans: B
(A) Serum (B) Plasma (C) Lymph (D) Cytosol Ans: B
📝 Pro Tip for AMU: Know the three simple plant tissues (parenchyma, collenchyma, sclerenchyma) with wall thickness, living/dead status. Xylem vs phloem comparison. Epithelial types — especially squamous (lining), ciliated (trachea). Connective — areolar (binds), adipose (fat), tendon vs ligament, bone vs cartilage. Muscle types — skeletal (voluntary, striated), smooth (involuntary, non-striated), cardiac (involuntary, striated, branched with intercalated discs).