While planning for an artificial hybridization programme involving dioecious plants, which of the following steps would not be relevant?
1. Bagging of the female flower
2. Dusting of pollen on the stigma
3. Emasculation
4. Collection of pollen
The phenomenon wherein, the ovary develops into a fruit without fertilisation is called:
1. | Parthenocarpy | 2. | Apomixis |
3. | Asexual reproduction | 4. | Sexual reproduction |
Flowers that have a single ovule in the ovary and are packed into inflorescence are usually pollinated by:
1. | Water | 2. | Bee |
3. | Wind | 4. | Bat |
Pollen grains lose viability within 30 minutes of their release in some members of:
1. | Rosaceae | 2. | Leguminosae |
3. | Poaceae | 4. | Solanaceae |
The majority of water plants like water hyacinth and water lily are pollinated by:
1. | Water | 2. | Wind |
3. | Insects | 4. | Both 2 and 3 |
At what temperature pollens can be stored for years in liquid nitrogen?
1. | 0°C | 2. | -100°C |
3. | -196°C | 4. | 4°C |
In angiosperms, the mature female gametophyte is represented by:
1. | Nucellus | 2. | Megaspore |
3. | MMC | 4. | Embryosac |
A typical angiosperm embryosac, at maturity, is:
1. | 8 celled and 8 nucleate | 2. | 8 celled and 7 nucleate |
3. | 7 celled and 8 nucleate | 4. | 7 celled and 7 nucleate |
Which of the following is not used by flowering plants as an outbreeding device?
1. | Lack of synchronization between pollen release and stigma receptivity. |
2. | Anther and Stigma placed at different levels. |
3. | Self-incompatibility. |
4. | Production of bisexual flowers. |
The pollen tube releases the two male gametes first into:
1. The vicinity of the egg cell.
2. The vicinity of polar nuclei.
3. In the cytoplasm of synergids.
4. In the cytoplasm of antipodals.