Q. No.Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called:
1. Efficiency index
2. Plasticity
3. Norm of reaction
4. Developmental noise
Identify the incorrectly matched pair:
| PGR | Chemical nature | |
| 1. | Auxins | Indole compounds |
| 2. | Cytokinin | Pyrimidine derivatives |
| 3. | ABA | Carotenoid derivative |
| 4. | Gibberellic acid | Terpenes |
Identify the plant growth regulator that, though is largely an inhibitor but, can be placed in both plant growth promoter and plant growth inhibitor groups?
| 1. | Auxins | 2. | Gibberellins |
| 3. | Ethylene | 4. | Abscisic acid |
Identify the incorrectly matched pair:
| Scientist | PGR discovery | |
| 1. | Cousins | Ethylene |
| 2. | Kurosawa | Gibberellin |
| 3. | Skoog and Miller | ABA |
| 4. | F. W. Went | Auxin |
Auxin does not:
| 1. | Help to initiate rooting in stem cuttings |
| 2. | Promote female flowers in cucumbers |
| 3. | Prevent fruit and leaf drop in early stages |
| 4. | Promote abscission of older mature leaves and fruits |
Cytokinins do not help in:
| 1. | Production of new leaves |
| 2. | Lateral shoot growth |
| 3. | Adventitious shoot formation |
| 4. | Promotion of apical dominance |
Normally, when the seeds are mature, ethylene production increases and builds-up within the fruit, resulting in a climactic event that means:
| 1. | A sudden spurt of growth | 2. | Leaf expansion |
| 3. | Rise in respiratory rate | 4. | Death of radicle |
Which PGR stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stress?
| 1. | Cytokinin | 2. | Giberrellin |
| 3. | ABA | 4. | Ethylene |
In most situations, which PGR acts as an antagonist to GAs?
| 1. | ABA | 2. | Ethylene |
| 3. | Cytokinin | 4. | Giberrellin |
The site of perception of light/dark duration in plants is:
1. Root apex
2. Shoot apex
3. Flower
4. Leaves
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