Primary and secondary growth are inhibited by:

1. Auxins

2. Gibberellins

3. Abscisic acid

4. Cytokinins

Fruit and leaf drop at early stages can be prevented by the application of 
1. Cytokinins
2. ethylene
3. auxins
4. gibberellic acid 

you are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
(1) IAA and gibberellin 

(2) Auxin and cytokinin

(3) Auxin and abscisic acid

(4) Glbberellin & abscisic acid

Phytochrome is a 
(1) flavoprotein

(2) glycoprotein

(3) lipoprotein

(4) chromoprotein

The Avena curvature is used for bioassay of 
(1) GA₃

(2) IAA

(3) Ethylene

(4) ABA

Auxin can be bioassayed by

1. Avena coleoptile curvature

2. hydroponics

3. potometer

4. lettuce hypocotyl elongation

What causes a green plant exposed to the light on only one side, to bend toward the

source of light as it grows?

1. Green plants need light to perform photosynthesis

2. Green plants seek light because they are phototropic

3. Light stimulates plant cells on the lighted side to grow faster

4. Auxin accumulates on the shaded side, stimulating greater cell elongation there

Dr. F Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly cut coleoptile stumps. Of what significance is this experiment?

1. It made possible the isolation and exact identification of auxin.

2. It is the basis for quantitative determination of small amounts of growth-promoting substances

3. It demonstrated polar movement of auxins

4. It supports the hypothesis that IAA is auxin

A few normal seedlings of tomato were kept in a dark room. After a few days they were

found to have become white-coloured like albinos. Which of the following terms will you

use to describe them?

1. Mutated

2. Embolised

3. Etiolated

4. Defoliated

Which one of the following growth regulators is known as "stress hormone" ?

1. abscisic acid

2. Ethylene

3. GA₃             

4. lndole acetic acid