NCERT solutions for class 9 science

Chapter 06-Tissues-Exercise Solutions

NCERT TEXTBOOK EXERCISES Page Number 79

Q.1. Define the term “tissue”.
Answer. A tissue is a group or collection of similar or dissimilar cells that perform or help to perform a common function and have a common origin.

Q.2. How many types of elements together make up the xylem tissue? Name them.
Answer. Four types of elements together make up Xylem tissue. They are:
(i) Tracheids
(ii) Vessels
(iii) Xylem parenchyma
(iv) Xylem fibres.
Q.3. How are simple tissues different from complex tissues in plants?
Or
Differentiate between simple tissues and complex tissues.
Answer.

 

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

 

Q.5. What are the functions of the stomata?
Answer. Stomata are present on the epidermis of the leaf.
Functions :
(i) Exchange of gases with the atmosphere.
(ii) Transpiration i.e. the loss of water in the form of water vapour.
Q.6. Diagramatically show the difference between the three types of muscle fibres.
Ans.

 

Q.7. What is the specific function of the cardiac muscles?
Answer. Cardiac muscles are involuntary muscles present in heart. They help in the rhythmic, contraction
and relaxation of heart.
This means that the pumping of blood through heart results from the continuous relaxation
and contraction of cardiac muscle.

Q.8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location of the body.
Answer.

 

Q.9. Draw a labelled diagram of a neuron.

 

Q.10. Name the following :
(a) Tissue that forms 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 whose matrix is fluid
(f) Tissue present in the brain
Answer. (a) Simple squamous epithelium
(b) Tendon
(c) Phloem
(d) Adipose tissue
(e) Blood
(f) Nervous tissue
Q.11. Identify the type of tissue in the following:
Skin, bark of a tree, bone, lining of kidney tubule, vascular bundle.
Answer. Skin : Squamous epithelium.
Bark of tree : Epidermal tissue (cork) with a chemical called suberin (that makes it impervious to gases and water).
Bone : Connective tissue.
Lining of kidney tubule : Cuboidal epithelium.
Vascular bundles : Conductive tissue. (xylem and phloem)
Q.12. Name the regions in which parenchyma tissue is present.
Answer. Parenchyma is a simple permanent tissue, which forms the basic packing tissue. It is present in the cortex and pith of stem and roots. It is also present in the mesophyll of leaves.
Q.13. What is the role of epidermis in plants?
Answer. The entire surface of a plant has the outer covering of epidermis. It protects all the parts of
a plant. Epidermis protects the plants against loss of water, mechanical injury and invasion by parasitic fungi.
Q.14. How does the cork act as protective tissue?
Answer. Cork is several layers thick. The cells are dead and compactly arranged without intercellular space. They have a chemical called ‘Suberin’ in their walls, Suberin makes cork cell impervious to gases and water. Thus, it protects underlying tissues from desication.
Q.15. Complete the table :

 

Answer.