Short Answer Questions – I - 2 Marks

Q1. What happens to the cells formed by meristematic tissue?

Ans. The cells formed by meristematic tissue take up a specific role and lose their ability to divide. As a result, they form a permanent tissue. This process of taking up a permanent shape, size and function is called differentiation.

Q2. Why is the epidermis present as a thick waxy coating of cutin in desert plants?

Ans. A thick waxy coating of cutin is present in desert plants to prevent excessive loss of water during transpiration. Due to this, plants can survive in scarcity of water in deserts.

Q3. Write a short note on 'phellogen'.

Ans. As plants grow older, the outer protective tissue undergoes certain changes. A layer of secondary meristem develops which is called as phellogen. It is also known as cork cambium. It replaces epidermis of stem and roots.

Q4. How are glandular epithelium formed?

Ans. An epithelial cell often acquires additional specialisation as gland cells, which can secrete substances at the epithelial surface. Sometimes, a portion of the epithelial tissue folds inward and a multicellular gland is formed. This is glandular epithelium.

Q5. Describe the function of bones.

Ans. Bones form the framework that supports the body. It also anchors the muscles and serve as storage site of calcium and phosphate. It provides shape to the body and protects vital body organs such as brain, lungs, tissue, etc.

Q6. How are messages conveyed from one place to another within the body?

Ans. Nervous tissue is made up of neurons that receive and conduct impulses. Neurons are highly specialised for being stimulated and then transmitting the stimulus very rapidly from one place to another within the body. Impulses are the passage of electrical activity along the axon of a nerve cell.

Q7. (a) What is the lining of blood vessels made up of?
(b) What is the lining of small intestine made up off?
(c) What is the lining of kidney tubules made up of?
(d) Where are the epithelial cells with cilia found?

Ans.

(a) Squamous epithelium           (b) Columnar epithelium
(c) Cuboidal epithelium             (d) Respiratory tract