Chapter 6: Tissues - NCERT Solutions
Intext Questions (Page No- 61)
1. What is a tissue?
Answer - A tissue is a group of similar cells that work together to perform a specific function.
2. What is the utility of tissues in multi-cellular organisms?
Answer - Tissues help in performing specific functions efficiently by organizing similar cells, thereby supporting the organism's growth, repair, and overall functioning.
Intext Questions (Page No- 65)
1. Name types of simple tissues.
Answer - The types of simple tissues are parenchyma, collenchyma, and sclerenchyma.
2. Where is apical meristem found?
Answer - Apical meristem is found at the tips of roots and shoots.
3. Which tissue makes up the husk of coconut?
Answer - The husk of coconut is made up of sclerenchyma tissue.
4. What are the constituents of phloem?
Answer - The constituents of phloem are sieve tubes, companion cells, phloem parenchyma, and phloem fibres.
Intext Questions (Page No- 69)
1. Name the tissue responsible for movement in our body.
Answer - The tissue responsible for movement in our body is muscular tissue.
2. What does a neuron look like?
Answer - A neuron consists of a cell body (cyton), long extensions called dendrites, and a single long axon. It looks like a star-shaped cell with a tail.
3. Give three features of cardiac muscles.
Answer -
- Cardiac muscles are involuntary in nature.
- They are striated (striped) in appearance.
- They have branched fibres and usually one nucleus per cell.
4. What are the functions of areolar tissue?
Answer - Areolar tissue fills the space inside organs, supports internal organs, and helps in tissue repair. It also holds tissues together and acts as a packing tissue.
Exercises
1. Define the term “tissue”.
Answer - A tissue is a group of similar cells that perform a specific function in an organism.
2. How many types of elements together make up the xylem tissue? Name them.
Answer - Xylem tissue is made up of four types of elements: tracheids, vessels, xylem fibres, and xylem parenchyma.
3. How are simple tissues different from complex tissues in plants?
Answer -
| Simple Tissues | Complex Tissues | |
|---|---|---|
| Composition | Made of only one type of cells | Made of more than one type of cells |
| Function | Performs basic functions like protection and support | Helps in transport of water, minerals, and food |
| Examples | Parenchyma, Collenchyma, Sclerenchyma | Xylem, Phloem |
4. Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.
Answer -
| Parenchyma | Collenchyma | Sclerenchyma | |
|---|---|---|---|
| Cell Wall | Thin cell wall made of cellulose | Cell wall thickened at corners with cellulose and pectin | Thick and lignified cell wall |
5. What are the functions of the stomata?
Answer -
- Exchange of gases (CO₂ and O₂) during photosynthesis and respiration
- Loss of water vapour through transpiration
6. Diagrammatically show the difference between the three types of muscle fibres.
Answer - Please refer to your textbook or diagram resources for visual representations. The three types are: striated, unstriated, and cardiac muscles.
7. What is the specific function of the cardiac muscle?
Answer - Cardiac muscles are responsible for the rhythmic contraction and relaxation of the heart to pump blood throughout the body.
8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.
Answer -
| Striated Muscles | Unstriated Muscles | Cardiac Muscles | |
|---|---|---|---|
| Structure | Long, cylindrical, multinucleate with striations | Long, spindle-shaped, uninucleate without striations | Branched, striated with one nucleus per cell |
| Location | Attached to bones (skeletal) | Walls of internal organs (e.g., stomach, intestines) | Walls of the heart |
9. Draw a labelled diagram of a neuron.
Answer - Please refer to your textbook or diagram resources for a labelled neuron diagram showing dendrites, cell body, axon, and axon terminals.
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.
Answer -
- (a) Epithelial tissue
- (b) Tendon
- (c) Phloem
- (d) Adipose tissue
- (e) Blood
- (f) Nervous tissue
11. Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.
Answer -
- Skin – Epithelial tissue
- Bark of tree – Protective tissue (Cork)
- Bone – Connective tissue
- Lining of kidney tubule – Cuboidal epithelium
- Vascular bundle – Conducting tissue (Xylem and Phloem)
12. Name the regions in which parenchyma tissue is present.
Answer - Parenchyma tissue is present in the soft parts of the plant such as the cortex and pith of stems and roots, mesophyll of leaves, and the pulp of fruits.
13. What is the role of epidermis in plants?
Answer - The epidermis acts as a protective layer in plants. It prevents water loss, provides protection against mechanical injury and infection, and in leaves, it may have stomata for gas exchange.
14. How does the cork act as a protective tissue?
Answer - Cork cells are dead and have suberin in their walls, making them impermeable to water and gases. This helps protect the plant from dehydration, infection, and physical damage.
15. Complete the following chart:
Answer -
| Column 1: Tissue | Column 2: Location | Column 3: Function |
|---|---|---|
| Parenchyma | Soft parts of the plant (cortex, pith, leaf) | Storage, photosynthesis, and healing |
| Collenchyma | Leaf stalks and below the epidermis in dicot stems | Provides mechanical support and flexibility |
| Sclerenchyma | Hard parts of the plant like seed coats, nut shells | Provides strength and rigidity |
| Xylem | Vascular bundles | Transport of water and minerals |
| Phloem | Vascular bundles | Transport of food |