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. Gibberellin and abscisic acid

Phytochrome is a
1. flavoprotein
2. glycoprotein
3. lipoprotein
4. chromoprotein

The Avena curvature is used for bioassay of
1. ${\mathrm{GA}}_3$
2. IAA
3. Ethylene
4. ABA

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

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. ${\mathrm{GA}}_3$ 
4. lndole acetic acid

During seed germination, its stored food is mobilised by:

Phototropic curvature is the result of uneven distribution of.
1. gibberellin
2. phytochrome
3. cytokinins
4. auxin

Coiling of garden pea tendrils around any support is an example of
1. thigmotaxis
2. thigmonasty
3. thigmotropism
4. thermotaxis