In order to increase the yield of sugarcane crops, which of the following plant growth regulators should be sprayed?
1.
Ethylene
2.
Auxins
3.
Gibberellins
4.
Cytokinins
Removal of shoot tips is a very useful technique to boost the production of tea leaves. This is because:
| 1. | Gibberellins prevent bolting and are inactivated. |
| 2. | Auxins prevent leaf drop at early stages. |
| 3. | Effect of auxins is removed and the growth of lateral buds is enhanced. |
| 4. | Gibberellins delay the senescence of leaves. |
The plant hormone, _______________ , plays a role in closing of stomata.
1. auxin
2. Cytokinin
3. gibberellin
4. ABA
When a plant is flooded it often increases its production of
1. cytokines
2. ethylene
3. gibberellins
4. all of the above
The phytohormone which is supposed to be one of the factor responsible for regulating the opening and closing of stomata:
1. ABA
2. GA
3. IBA
4. Kinetin
What is the site of perception of photoperiod necessary for induction of flowering in plants?
1. Leaves
2. Lateral buds
3. Pulvinus
4. Shoot apex
It takes a very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield?
1. Cytokinin and Abscisic acid
2. Auxin and Ethylene
3. Gibberellin and Cytokinin
4. Gibberellin and Abscisic acid
1. cytokinin
2. Ethylene
3. abscissic acid
4. gibberellic acid
| 1. | Delay leaf senescence |
| 2. | Cause leaf abscission |
| 3. | Promote seed dormancy |
| 4. | Promote stomatal closing |
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