NIOS Biology Intext Solutions Chapter 20

Table of Contents

1. Distinguish between growth and development.

Ans:

Growth: Increase in the number and size of a cell, organ, or organism.
Development: Series of qualitative & quantitative changes including growth, differentiation, and maturation.

2. What is differentiation?

Ans: Process of change in cells, tissues, or organs to carry out different functions.

3. What role does it play in plant growth and development?

Ans: Similar cells organise to form a group called a tissue to perform a particular function

1. Name the plant hormones concerned with the following:

(i) Elongation of cell.

(ii) Shedding of leaves

(iii) Breaking seed dormancy

Ans:

2. Mention two functions of auxin

Ans:

3. What is the difference between dedifferentiation and redifferentiation?

Ans:

Dedifferentiation: Process by which precursor cells become distinct cell types to perform a specific function.
Redifferentiation: Process by which the plant cells, while undergoing dedifferentiation, lose their capacity to divide once again but mature to perform specific functions.

4. Which two hormones are essential for vascular tissue differentiation?

Ans: Auxin and cytokinin.

1. Distinguish between phototropism and geotropism

Ans:

2. Give two examples of turgor movement

Ans:

Closure of leaves at the fall of darkness
Dropping of leaves on touch
Closing the leaves of the Venus flytrap to catch an insect that lands on it (any two)

20 Growth and Development in Plants