Auxins:
I: | promote flowering in pineapples |
II: | induce parthenocarpy in tomatoes |
III: | like 2,4-D kill monocot weeds |
IV: | control xylem differentiation |
1. Only I and II are correct
2. Only III is incorrect
3. I, II, III and IV are correct
4. Only I and IV are incorrect
I: | Spraying sugarcane crop with gibberellins increases the yield by as much as 20 tonnes per acre. |
II: | Sugarcane stores carbohydrates as sugar in their stems and spraying sugarcane crop with gibberellins increases the length of the stem. |
I: | They can be used to increase the length of grape stalks. |
II: | They can elongate and improve the shape of apple. |
III: | They speed up malting process in brewing industry. |
IV: | They hasten the maturity period of juvenile conifers. |
V: | They promote bolting in many plants with rosette habit. |
1. 2 | 2. 3 |
3. 4 | 4. 5 |
1. | They were discovered as kinetin, a modified form of adenine. |
2. | Zeatin was isolated from corn-kernels and coconut milk. |
3. | Kinetin occurs widely in almost all plants. |
4. | Natural cytokinins are synthesized in region where rapid cell division occurs. |
I: | Help produce new leaves, chloroplasts in leaves, lateral shoot growth and adventitious root formation. |
II: | Help overcome the apical dominance. |
III: | Promote nutrient mobilisation, which helps in the delay of leaf senescence. |
1. Only I and II | 2. Only I and III |
3. Only II and III | 4. I, II and III |
1. | ABA | 2. | IAA |
3. | Ethylene | 4. | GA |
I: | The most widely used compound as source of ethylene is ethephon. |
II: | Ethephon in an aqueous solution is readily absorbed and transported within the plant and releases ethylene slowly. |