In a tissue culture experiment, the undifferentiated callus will develop shoot buds if:
1. amount of auxin and cytokinin is equal in the medium
2. amount of auxin is more than the amount of cytokinin in the medium
3. amount of cytokinin is more than the amount of auxin in the medium
4. the medium lacks auxin and cytokinin but has other plant growth regulators
Plant growth regulators do not:
1. act by altering gene expression.
2. have multiple effects.
3. function independently of other hormones.
4. control cell division and cell differentiation
The control of apical dominance is due to interaction of auxins, cytokinins and a newly discovered plant hormone called as:
1. Brassinosteroids
2. Jasmonates
3. Salicylic acid
4. Strigolactones
To promote stem elongation, gibberellins act in concert with:
1. | Auxins | 2. | Cytokinins |
3. | Ethylene | 4. | ABA |
Identify the incorrect statement regarding gibberellins:
1. All are acidic
2. Cause bolting in plants with rosette habit
3. Delay the maturity period of juvenile conifers
4. Speed up malting process in brewing industry
The removal or inactivation of which of the following will lead to germination of many types of dormant seeds?
1. | ABA | 2. | Ethylene |
3. | Cytokinins | 4. | Gibberellins |
Many mutants that are especially prone to wilting are deficient in:
1. ABA
2. Ethylene
3. Cytokinins
4. Gibberellins
The fact that various plant hormones can have different effects at different concentrations can explain:
1. Need of photoperiodism for flowering in plants.
2. Plant hormones being needed in vary high amounts.
3. Antagonism between auxin and cytokinin in the control of apical dominance.
4. Cell elongation stimulation in apical meristems and inhibition axillary buds by auxins.
Hyponastic response in submerged plants may be due to auxin and:
1. ABA
2. Ethylene
3. Cytikinin
4. Gibberellins
The ‘triple response to mechanical stress’ is related to the plant growth regulator:
1. Ethylene
2. ABA
3. Auxin
4. Cytokinin