What are plant growth regulators? Name any four different chemical nature of them with one example of each.

5

(a)

Mention the factors which prove that phytohormones act synergistically or antagonistically.

5

(a)

Define differentiation? Also, give details about how can you distinguish between dedifferentiation and redifferentiation?

5

(a)

Describe briefly:
(a) Arithmetic growth
(b) Geometric growth
(c) Sigmoid growth curve
(d) Absolute and relative growth rates

5

(a)

Describe briefly Geometric growth

5

(a)

What do you understand by photoperiodism and vernalisation? Describe their significance.

5

(a)

Write Short Notes on Gibberellins

5

(a)

Write Short Notes on Ethylene

5

(a)

Write Short Notes on Abscisic Acid

5

(a)

Which are the different phases of growth in a plant? Describe with the help of suitable diagrams.

5

(a)