During microsporogenesis, meiosis occurs in:
1. | Endothecium | 2. | Microspore mother cells |
3. | Microspore tetrads | 4. | Pollen grains |
In over 60 % of angiosperms, pollen grains are shed at:
1. | 2-celled stage | 2. | 3-celled stage |
3. | 4-celled stage | 4. | 1-celled stage |
Statement I: | It shows a pollen tetrad. |
Statement II: | The four microspores are contained by callose walls. |
1. | Statement I is correct, Statement II is correct. |
2. | Statement I is incorrect, Statement II is correct. |
3. | Statement I is correct, Statement II is incorrect. |
4. | Statement I is incorrect, Statement II is incorrect. |
Statement I: | The spindle formation as seen in A is strictly symmetric. |
Statement II: | The larger cell [B] is the generative cell and the smaller cell [C] is the vegetative cell. |
1. | Statement I is correct, Statement II is correct |
2. | Statement I is incorrect, Statement II is correct |
3. | Statement I is correct, Statement II is incorrect |
4. | Statement I is incorrect, Statement II is incorrect |
‘Germ pore’ in pollen in angiosperms:
1. | is a part of pollen intine where sporopollenin is present |
2. | is a part of pollen intine where sporopollenin is absent |
3. | is a part of pollen exine where sporopollenin is present |
4. | is a part of pollen exine where sporopollenin is absent |
Identify the incorrect statement regarding Parthenium hysterophorus:
1. | Its pollens are a very common cause of severe respiratory allergies. |
2. | It was introduced in India accidentally as a contaminant in wheat. |
3. | It is a native of tropical America |
4. | It is non-invasive and limited to certain pockets in India only |
At what temperature pollens can be stored for years in liquid nitrogen?
1. | 0°C | 2. | -100°C |
3. | -196°C | 4. | 4°C |
Pollen grains lose viability within 30 minutes of their release in some members of:
1. | Rosaceae | 2. | Leguminosae |
3. | Poaceae | 4. | Solanaceae |