Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): | When the roots begin to sense a water shortage in the soil, abscisic acid (ABA) is released. |
Reason (R): | ABA plays a primary role in closing stomata in response to drought. |
In the light of the above statements choose the correct answer from the options given below:
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
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.
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.
4. lndole acetic acid
During seed germination, its stored food is mobilised by:
1. | ethylene | 2. | cytokinin |
3. | ABA | 4. | gibberellin |
Phototropic curvature is the result of uneven distribution of.
1. gibberellin
2. phytochrome
3. cytokinins
4. auxin