9th Science Chapter 6 Tissues

 NCERT Solutions For Class 9 Science Chapter 6 Tissues

IN-TEXT QUESTIONS SOLVED

NCERT Textbook for Class 9 Science – Page 69

Question 1. What is a tissue? 

Ans: A tissue is a group of similar cells that work together to perform a specific function.

The cells in a tissue have a common origin and similar structure.
Tissues make the body more efficient by dividing work among groups of cells.

Example: Muscle tissue helps in movement, and blood (a connective tissue) transports oxygen.

Question 2. What is the utility of tissues in multicellular organisms?

Ans:  Tissues make the body of multicellular organisms more organized, efficient, and capable of doing complex tasks — helping the organism survive and grow better.

 1. Divide Work (Specialization) - Different tissues perform specific functions.

Example: Muscle tissue helps in movement, nerve tissue carries signals, xylem transports water in plants.

2. Increase Efficiency - Since each tissue does a particular job, the function is performed more efficiently and quickly.

3. Save Energy - Cells are not doing everything individually — tissues share the workload, so less energy is wasted.

4. Enable Complex Body Structures - Tissues group together to form organs (like heart, lungs, roots), which can perform complex functions in the body.

5. Allow Growth and Repair - Some tissues, like meristematic tissue in plants, help in growth.

Others help repair damaged parts (e.g., skin tissue regenerates).

Class 9 Science NCERT Textbook – Page 74

Question 1. Name types of simple tissues

Ans : There are three main types of simple tissues:

1. Parenchyma
Special types: Chlorenchyma , Aerenchyma 

2. Collenchyma

3. Sclerenchyma

Question 2. Where is apical meristem found?

Ans : The apical meristem is found at the tips of roots and shoots in plants.

Root tips – helps the root grow downward into the soil.

Shoot tips – helps the stem grow upward and form new leaves, flowers, and branches.

Question 3. Which tissue makes up the husk of coconut?

The husk of coconut is made up of a simple permanent tissue called sclerenchyma, more specifically, sclerenchyma fibres.

The fibrous husk is full of sclerenchyma fibres, which make it strong and tough — perfect for protecting the seed inside.

Question 4. What are the constituents of phloem?

Phloem is a complex permanent tissue that helps in transporting food (mainly sugars) from the leaves to other parts of the plant.

Constituent                 Description

1. Sieve tubes                 Long, tube-like cells with pores (sieve plates); carry food.

2. Companion cells         Help sieve tubes function; have nucleus and control activity.

3. Phloem parenchyma Stores food and helps in lateral transport.

4. Phloem fibres         Only dead component; gives strength and support.

Class 9 Science NCERT Textbook – Page 78

Question 1. Name the tissue responsible for movement in our body.

Ans : The tissue responsible for movement in our body is called muscular tissue.

Helps in movement of body parts by contracting and relaxing.

Found in muscles attached to bones, in the heart, and in internal organs.

Question 2. What does a neuron look like?

Ans : A star-like center (cell body) with branchy arms (dendrites) on one side, and a long wire-like tail (axon) on the other — that’s a neuron!

Parts of a Neuron:

1. Cell Body (Soma): Central part of the neuron.
                                  Contains the nucleus and other organelles.
                                  Looks like a round area with small branches.

2. Dendrites:  Short, branch-like extensions from the cell body.
                      Receive signals from other neurons.

3. Axon:    A long tail-like structure coming out of the cell body.
                 Carries messages away from the neuron to other cells (neurons, muscles, glands).
                 May be covered by a myelin sheath to speed up the signal

Question 3. Give three features of cardiac muscles.

Ans :  Features of Cardiac Muscles:

1. Involuntary in Nature
Cardiac muscles work automatically — we don’t control them consciously.
They keep the heart beating without us thinking about it.

2. Branched and Cylindrical
The muscle cells are branched and cylindrical in shape.
They form a network to help the heart contract smoothly and in rhythm.

3. Have Intercalated Discs
These are special connections between cells that help in faster transmission of signals, ensuring coordinated heartbeats.

Cardiac muscles are uninucleated (each cell has one nucleus).
They never get tired — they keep working throughout life!

Question 4. What are the Functions of areolar tissue?

Ans : Functions of Areolar Tissue

Areolar tissue is a type of connective tissue found in animals. It acts like a soft packing material between organs.

1. Binds Organs Together
It connects skin to muscles, fills spaces between organs, and holds them in place.

2. Supports and Protects Organs
Acts like cushioning, protecting internal organs from damage.

3. Helps in Repair of Tissues
Plays a role in healing wounds by helping regenerate tissues.

4. Fights Infections

Areolar tissue is found under the skin, around blood vessels, nerves, and even between muscles — it's like the body's natural bubble wrap!

Questions From NCERT Textbook for Class 9 Science

Question 1. Define the term “tissue”.

Ans: 
A tissue is a group of similar cells that work together to perform a specific function in the body.

Cells in a tissue have the same origin, structure, and function.
Tissues make the body more organized and efficient.
Example: Muscle tissue helps in movement, xylem transports water in plants.

Question 2. How many types of elements together make up the xylem tissue? Name them.

Ans : It is made up of 4 different types of elements:

Tracheids    -     Long, tube-like dead cells with tapering ends.
                          Help in water transport and support.

Vessels    -        Wider, cylindrical tube-like dead cells joined end to end.
                        Main water-conducting elements in angiosperms.

Xylem Parenchyma    -    The only living component of xylem.
                                        Stores food and helps in sideways transport of water.

Xylem Fibres    -     Dead and supportive in function.
                                Provide mechanical strength.

Question 3. How are simple tissues different from complex tissues in plants?

Ans: 

Difference Between Simple and Complex Tissues in Plants

Feature	Simple Tissues	Complex Tissues
Number of Cell Types	Made of only one type of cell	Made of more than one type of cell
Function	All cells perform similar functions	Different cells perform different functions
Main Function	Mostly for support, storage, and protection	For transport of water and food
Examples	Parenchyma, Collenchyma, Sclerenchyma	Xylem, Phloem
Cell Structure	Cells are mostly similar in structure	Cells are different in structure and function

Question 4. Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall

Ans: 

Comparison Based on Cell Wall

Tissue Type	Cell Wall Type
Parenchyma	Thin and uniform primary cell wall made of cellulose
Collenchyma	Unevenly thickened walls, especially at corners, made of cellulose and pectin
Sclerenchyma	Thick, lignified (woody) walls; very hard and rigid

Question 5. What are the functions of stomata?

Ans:   

Stomata are tiny openings (pores) found mainly on the underside of leaves. They are surrounded by guard cells that control their opening and closing.

Main Functions:

1. Gas Exchange -   Allow carbon dioxide to enter the leaf for photosynthesis
                                Let oxygen (a byproduct of photosynthesis) exit the leaf

2. Transpiration -  Help in the loss of excess water vapor from the plant through evaporation
                             This process helps in cooling the plant and pulling water from roots

3. Maintain Water Balance -  Guard cells open and close the stomata to control water loss                                                   during dry conditions

Question 6. Diagrammatically show the difference between the three types of muscle fibres.

Ans : 

Striated muscles

(1) They are connected to bones (Skeletal muscles).
(2) They are voluntary muscles.
(3) The cells are long, cylindrical with many nucleus and are unbranched.

Smooth muscles

(1) They are found in alimentary canal and lungs.
(2) They are involuntary muscles.
(3) They are spindle in shape and have single nucleus.

Cardiac muscles

(1) They are found in heart.
(2) They are involuntary in action.
(3) They are branched and have one nucleus.

Question 7. What is the specific function of the cardiac muscle?

Ans: To pump blood throughout the body by contracting and relaxing rhythmically and continuously.

Found only in the heart.
Works involuntarily (you don’t control it).
Contracts in a rhythmic and coordinated way to keep blood flowing.
Never tires — works nonstop from birth to death!

Question 8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and location in the body.

Ans: 

Types of Muscles: Comparison Table

Feature	Striated Muscles	Unstriated Muscles	Cardiac Muscles
Other Name	Skeletal / Voluntary muscles	Smooth / Involuntary muscles	Involuntary heart muscle
Structure	Long, cylindrical, multinucleated, and striped (striated)	Spindle-shaped, uninucleated, and no striations	Cylindrical, branched, striated, and uninucleated
Location in Body	Attached to bones (arms, legs, face, etc.)	Walls of internal organs (stomach, intestine, bladder)	Found only in the heart
Control	Voluntary (we control them)	Involuntary (automatic)	Involuntary (automatic and rhythmic)
Fatigue	Can get tired	Do not get tired easily	Never gets tired

Question 9. Draw a labelled diagram of neuron

Ans : 

Question 10. Name the following. 

(a) Tissue that forms the inner lining of our mouth. 

(b) Tissue that connects muscle to bone in humans. 

(c) Tissue that transports food in plants. 

(d) Tissue that stores fat in our body. 

(e) Connective tissue with a fluid matrix. 

(f) Tissue present in the brain.

Ans: 

Name the following:

(a) Tissue that forms the inner lining of our mouth
➡️ Epithelial tissue (specifically squamous epithelium)

(b) Tissue that connects muscle to bone in humans
➡️ Tendon

(c) Tissue that transports food in plants
➡️ Phloem

(d) Tissue that stores fat in our body
➡️ Adipose tissue

(e) Connective tissue with a fluid matrix
➡️ Blood

(f) Tissue present in the brain
➡️ Nervous tissue

Question 11. Identify the type of tissue in the following: Skin, bark of tree, bone, lining of kidney tubule, vascular bundle.

Ans 

Identify the Tissue Types:

Structure	Type of Tissue
Skin	Epithelial tissue
Bark of tree	Protective tissue (Cork or dead phloem)
Bone	Connective tissue
Lining of kidney tubule	Cuboidal epithelial tissue
Vascular bundle	Complex permanent tissue (includes xylem and phloem)

Question 12. Name the regions in which parenchyma tissue is present.

Ans:

Regions Where Parenchyma Tissue is Present:

Parenchyma is a simple permanent tissue found in most parts of a plant. It is mainly responsible for storage, photosynthesis, and healing.

Common Regions:

1. Cortex and pith of stems and roots

2. Mesophyll of leaves (especially palisade and spongy parenchyma for photosynthesis)

3. Flesh of fruits

4. Seeds (to store food)

5. Xylem and phloem (as xylem parenchyma and phloem parenchyma)

6. Petiole and flower parts

Question 13. What is the role of epidermis in plants?

Ans: 

Role of Epidermis in Plants

The epidermis is the outermost layer of cells in plants. It covers leaves, stems, roots, and other parts.

✅ Main Functions:

1. Protection

   • Acts as a protective barrier against mechanical injury, water loss, and infection by pathogens.

2. Prevents Water Loss

   • The epidermal cells often secrete a waxy coating called the cuticle that reduces evaporation from the surface.

3. Gas Exchange

   • Specialized pores called stomata in the epidermis allow carbon dioxide in and oxygen out for photosynthesis and respiration.

4. Absorption (in roots)

• In roots, the epidermis has root hair cells that help in absorbing water and minerals from the soil.

Question 14. How does the cork act as a protective tissue?

Ans: 

How Cork Acts as a Protective Tissue:

Cork (also called phellem) is a protective tissue that replaces the epidermis in older stems and roots of plants.

Protective Functions of Cork:

1. Prevents Water Loss

   • Cork cells are dead and have suberin (a waxy substance) in their walls, making them waterproof.

2. Protects Against Injury and Infection

   • Forms a thick outer layer that shields the plant from mechanical damage and invasion by pathogens (like bacteria or fungi).

3. Insulation

• Acts as a thermal insulator, protecting the plant from extreme temperatures.