Class 9 · ScienceNCERT 2026 Revised Syllabus
Chapter 3: Tissues in Action (0906CH03)
Exploration · Plant and animal tissues — structure and function.
Chapter code: 0906ch03 · Book: Exploration · Class 9 Science
Find complete NCERT solutions for Class 9 Science, Exploration Chapter 3. Every question has a clear, step-by-step answer for chapter code 0906CH03.
Pause and Ponder(5 questions)
1
Coconut husk fibres are hard and brittle; coriander leaf stalks are soft and flexible. Find out the reason.
School Level Solution
Ans.
Coconut husk fibres = sclerenchyma — dead cells with thick, lignified walls → hard and brittle. Coriander stalks contain collenchyma — living cells with cellulose/pectin deposits (not lignin) → flexible and soft.
2
Why is a thick cuticle advantageous for a desert plant but disadvantageous for a plant living underwater?
School Level Solution
Ans.
In desert plants, a thick cuticle reduces transpiration — conserves water. For underwater plants, the cuticle would block direct absorption of water, CO₂, and O₂ from the surrounding water, hindering photosynthesis and respiration.
3
Water absorbed by roots travels against gravity through xylem. How do dead xylem cells work with living leaf cells to keep water moving?
School Level Solution
Ans.
Living guard cells open stomata → water evaporates (transpiration). This creates negative pressure (suction) that pulls the continuous water column upward through dead xylem vessels via cohesion of water molecules.
4
What would happen if there were no stomata in the epidermis of stems or leaves?
School Level Solution
Ans.
Without stomata, CO₂ cannot enter and O₂ cannot exit → photosynthesis stops. Transpiration pull ceases → water and mineral transport from roots stops. The plant would overheat, wilt, and die.
5
Identify which joints are involved in classical/folk dance poses (Fig. 3.17) and what movement each allows.
School Level Solution
Ans.
Hip joint: ball-and-socket — movement in all directions. Knee joint: hinge — flexion and extension only. Ankle joint: hinge/gliding — up-down movement. Shoulder joint: ball-and-socket — wide range of arm movement.
Activities — How to Do(4 questions)
1
Activity 3.1 (onion root growth jars): place one onion bulb in each of two water jars; measure root lengths on days 1–3; on day 3 cut Jar B’s root tips by 1 cm and measure for four more days. What trend and inference do you expect?
School Level Solution
Ans.
Record lengths in Table 3.1 for both jars. Jar A: roots lengthen steadily. Jar B: after tip-cutting, growth stops. Inference: growth occurs at the root tip (apical meristem) — removing it removes the dividing cells, so elongation halts.
2
Activity 3.2 (everyday blood experiences): a cut oozes red blood and clots; an infection reddens and swells; exercise quickens breathing and reddens the face. Which blood components explain each?
School Level Solution
Ans.
Red colour: haemoglobin in RBCs (replaced every ~4 months). Clotting: platelets seal the injury. Exercise: muscles need more oxygen → faster breathing and blood flow → red face. Infection: WBCs gather → inflammation, pus, redness, swelling.
3
Activity 3.3 (identify connective tissues): perform the actions in Table 3.4 (e.g., bending, stretching body parts) and match each experience to a connective tissue in Fig. 3.12. How should you approach the matching?
School Level Solution
Ans.
Do each action and note what you feel: pull without stretch (tendon — muscle to bone); stretch and recoil (ligament — bone to bone); smooth cushioning (cartilage — joints, nose); rigidity (bone); flow/transport (blood). Study each tissue’s fibres and matrix in Fig. 3.12 to confirm.
4
Activity 3.4 (body-weight components): weigh yourself; multiply by average bone (~12–15%) and muscle (~30–50%) percentages for your age and gender; compare with classmates. Why do values differ, and what do bones and muscles contribute?
School Level Solution
Ans.
Example: 40 kg × 13% ≈ 5.2 kg bone; 40 kg × 40% ≈ 16 kg muscle. Values differ due to age, gender, exercise and body type. Bones give support and shape; muscles give movement and strength — together they form most of body weight.