NCERT Class 9 Science Chapter 3 Tissues in Action Solutions

Short Intro

“Tissues in Action” chapter explains how groups of similar cells work together to perform specific functions in plants and animals. This chapter covers plant tissues, animal tissues, meristematic tissues, epithelial tissues, connective tissues, muscles, nervous tissues, joints, and skeletal system. Below are complete step-by-step solutions with explanations for all textbook questions in simple Unicode format suitable for uploading on www.mymockmate.com.

Quick Information Box

Topic Details
Chapter Name Tissues in Action
Subject Science
Grade Class 9
Main Concepts Plant & Animal Tissues
Important Topics Meristematic Tissue, Permanent Tissue, Muscles, Joints
Difficulty Level Medium
Exam Importance Very High

Concepts Used (Topics Covered)

  • Tissue and division of labour
  • Plant tissues and animal tissues
  • Meristematic tissues
  • Permanent tissues
  • Xylem and phloem
  • Epithelial tissue
  • Connective tissue
  • Muscular tissue
  • Nervous tissue
  • Skeletal system
  • Types of joints
  • Musculoskeletal coordination

Important Formulas

Percentage Formula

Percentage=PartWhole×100\text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100Percentage=WholePart​×100

Average Formula

Average=Sum of ObservationsNumber of Observations\text{Average} = \frac{\text{Sum of Observations}}{\text{Number of Observations}}Average=Number of ObservationsSum of Observations​

Questions & Step-by-step Solutions with Explanation

Question 1

Meristematic tissues divide repeatedly. What property allows them to do this?

Answer

Correct Option: (iii)

Explanation

Meristematic cells have:

  • Thin cell walls
  • Dense cytoplasm
  • Large nucleus
  • No vacuoles

These features help them divide continuously.

Question 2

Which tissue malfunctions if food transport from leaves to roots stops?

Answer

Correct Option: (ii) Phloem

Explanation

Phloem transports prepared food from leaves to all parts of the plant.

Question 3

Why are epithelial tissues usually thin?

Answer

Correct Option: (iii)

Explanation

Thin epithelial layers help in:

  • Quick diffusion
  • Fast absorption
  • Efficient gas exchange

Question 4

Difference between straight-leg jump and normal jump?

Answer

  • In straight-leg jump, knees and ankles remain stiff.
  • In normal jump, knees and ankles bend naturally.
  • Bending absorbs shock and gives better balance.

Question 5

Which joint helps in bending knees and ankles?

Answer

Correct Option: (ii) Hinge Joint

Explanation

Hinge joints allow movement in one direction only.

Question 6 Assertion-Reason Answers

A

Answer

Correct Option: (iii)

Explanation

Assertion is true but reason is false because lungs have thin epithelial tissue for rapid diffusion.

B

Answer

Correct Option: (i)

Explanation

Cardiac muscles contain many mitochondria and rich blood supply, helping continuous contraction.

C

Answer

Correct Option: (iv)

Explanation

Assertion is false because ligaments connect bone to bone. Tendons connect muscle to bone.

D

Answer

Correct Option: (iii)

Explanation

Hinge joints move mainly in one plane, but sliding in all directions does not occur.

Question 7

(i) Interpretation of Graph

As age increases, diameter of teak tree also increases gradually.

(ii) Relation Between Diameter and Annual Rings

More annual rings indicate older tree age and greater stem diameter.

(iii) Tissue Responsible for Girth

Answer

Lateral meristem (cambium) is responsible for increase in girth.

Location

It is located along the circumference of the stem.

Question 8

(i) Which functions are affected by debarking?

  • Protection
  • Food transport

(ii) Which tissue may be affected?

Answer

Phloem tissue

(iii) Which function gets hampered?

Transport of food from leaves to other parts.

(iv) Assumptions

Assuming bark damage includes phloem injury. If only outer bark is removed, effects may be less severe.

Question 9

Which tissue provides flexibility in mango sapling?

Answer

Collenchyma tissue

Explanation

Collenchyma provides flexibility and support.

If replaced by sclerenchyma

The stem would become rigid and may break during strong winds.

Question 10

(i) Why did type B cutting grow?

Because type B had nodes containing intercalary meristem.

(ii) Difference between A and B

Type B contained buds/nodes while A did not.

(iii) Observation Made

Growth and sprouting of new shoots were observed.

(iv) Parameters to Keep Same

  • Water
  • Soil
  • Sunlight
  • Temperature
  • Size of cuttings

Question 11

Explanation

Simple tissues contain only one type of similar cells.

Complex tissues contain different types of cells working together for one function.

Example:

  • Xylem
  • Phloem

Question 12

Which tissue gives strength to coconut husk fibres?

Answer

Sclerenchyma

Explanation

Sclerenchyma has thick lignified walls providing toughness and strength.

Parenchyma cannot provide strength because its cells are soft and thin-walled.

Question 13

Is Vibha’s statement correct?

Answer

No

Explanation

Meristematic tissues are also present as:

  • Lateral meristem
  • Intercalary meristem

Question Neha can ask

“Why does grass regrow after cutting?”

Question 14

(i) Which cell has larger vacuole?

Answer

Plant cell

Reason

Plant cells require large vacuoles for storage and maintaining turgidity.

(ii) Assumption

Assuming both cells are mature and healthy.

Question 15

Questions to examine the statement

  • Does every tissue perform only one function?
  • Can one tissue perform multiple functions?
  • Are some tissues involved in both support and transport?

Examples

  • Parenchyma
  • Xylem
  • Epidermis

Common Mistakes

  • Confusing xylem and phloem
  • Writing tendon instead of ligament
  • Forgetting that sclerenchyma cells are dead
  • Mixing voluntary and involuntary muscles
  • Confusing hinge joint with pivot joint

Exam Tips

  • Learn functions of all tissues in table form.
  • Practice diagrams of neuron, muscles and joints.
  • Remember examples of each tissue.
  • Revise differences between plant and animal tissues.
  • Focus on assertion-reason questions carefully.

Practice MCQs

1. Which tissue transports water in plants?

A. Phloem
B. Xylem
C. Epidermis
D. Collenchyma

Answer

B. Xylem

2. Which muscle is involuntary and striated?

A. Skeletal
B. Smooth
C. Cardiac
D. Tendon

Answer

C. Cardiac

3. Which tissue forms outer covering of body?

A. Nervous
B. Epithelial
C. Muscular
D. Connective

Answer

B. Epithelial

4. Which joint is present in shoulder?

A. Pivot
B. Hinge
C. Fixed
D. Ball and socket

Answer

D. Ball and socket

FAQ Section

Q1. What is a tissue?

A tissue is a group of similar cells performing a specific function.

Q2. What are the main types of plant tissues?

Meristematic and permanent tissues.

Q3. Which tissue transports food in plants?

Phloem transports food.

Q4. Which tissue helps in movement?

Muscular tissue helps in movement.

Q5. Which joint allows circular movement?

Ball and socket joint.

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