Which of the following is the site for perception of light/dark in plants?
1. Root apex
2. Shoot apex
3. Leaves
4. Flower
A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely
1. cause increased flower production.
2. have no effect upon flowering.
3. inhibit flowering.
4. stimulate flowering.
Which of the following statements about plant hormones is false?
1. The growth of plants in nature is probably regulated by a combination of growth-stimulating and growth-inhibiting hormones.
2. Abscisic acid generally promotes growth.
3. Gibberellins stimulate cell enlargement.
4. Cytokinins promote cell division.
At the root apex the cells of the meristematic region are not characterized by:-
1. Being rich in protoplasm
2. Abundant plasmodesmatal connections
3. A cell wall that is primary in nature
4. Having small inconspicuous nuclei
All the following plants are biennials except:-
1. Sugarbeet
2. Cabbages
3. Carrots
4. Wheat
Identify the option where all the columns are not correctly matched:
|
PGR |
Nature |
Actions |
1. |
Auxin |
Indole compounds |
Apical dominance, Flowering in pineapples, Parthenocarpy in tomatoes |
2. |
Cytokinin |
Adenine derivative |
Cell division, Adventitious shoot formation, Delay in leaf senescene |
3. |
Gibberellin |
Terpene |
Increase in length |
4 . |
ABA |
Carotenoid derivative |
Closure of stomata in water stress, inducing seed dormancy, inducing flowering in mango |
The PGR used to induce parthenocarpy in tomatoes is:-
1. Auxin
2. Gibberellin
3. Cytokinin
4. ABA
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