Differentiation of shoot is controlled by:
1. High auxin : cytokinin ratio
2. High cytokinin : auxin ratio
3. High gibberellin : auxin ratio
4. High gibberellin : cytokinin ratio
Nicotiana sylvestris flowers only during long days and N. tabacum flowers only during short days. If raised in the laboratory under different photoperiods, they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason for considering N. sylvestris and N. tabacum to be separate species:
1. They cannot interbreed in nature
2. They are reproductively distinct
3. They are physiologically distinct
4. They are morphologically distinct
Coconut milk factor is:
1. An auxin
2. A gibberellin
3. Abscisic acid
4. Cytokinin
What breaks the dormancy of potato tuber:
1. Gibberellin
2. IAA
3. ABA
4. Ethylene
The hormone responsible for senescence:
1. ABA
2. Auxin
3. GA
4. Cytokinin
Which of the following prevents the fall of fruits:
1.
2. NAA
3. Ethylene
4. Zeatin
The proteinaceous pigment which controls the activities concerned with light:
1. Phytochrome
2. Chlorophyll
3. Anthocyanin
4. Carotenoids
Seed dormancy is due to:
1. | Ethylene | 2. | Abscisic acid |
3. | IAA | 4. | Starch |