Q. No.In animals exhibiting external fertilization:
| 1. | the offspring are less prone to predation |
| 2. | the reproduction is independent of water |
| 3. | there is synchrony between sexes for the release of gametes |
| 4. | the number of female gametes are highly reduced |
The number of chromosomes in the shoot-tip cells of a maize plant is 20. The number of chromosomes in the microspore mother cells of the same plant shall be:
1. 20
2. 10
3. 40
4. 15
Organisms relying completely on external fertilization are almost always likely to be found in:
1. Tropical forests
2. Moist environments
3. Aquatic habitats
4. Dry, arid conditions
Match each item in Column I with one item in Column II and chose your answer from the codes given below.
|
Column I (plant) |
Column II (vegetatively propagated by) |
||
| I. | Pistia | 1. | Stem |
| II. | Asparagus | 2. | Root |
| III. | Kalanchoe | 3. | Leaves |
Codes:
| Options: | I | II | III |
| 1. | 1 | 2 | 3 |
| 2. | 2 | 1 | 3 |
| 3. | 2 | 3 | 1 |
| 4. | 1 | 3 | 2 |
The process of sexual reproduction which involves meiosis and syngamy is:
| 1. | Apomixis | 2. | Amphimixis |
| 3. | Agamospermy | 4. | Diplospory |
There is no natural death in single-celled organisms like Amoeba and bacteria because:
1. They cannot reproduce sexually
2. They reproduce by binary fission
3. Parental body is distributed among the offspring
4. They are microscopic
Given below are a few statements related to external fertilization. Choose the correct statements.
| i. | The male and female gametes are formed and released simultaneously. |
| ii. | Only a few gametes are released into the medium. |
| iii. | Water is the medium in a majority of organisms exhibiting external fertilization. |
| iv. | Offspring formed as a result of external fertilization have a better chance of survival than those formed inside an organism. |
| 1. | iii and iv | 2. | i and iii |
| 3. | ii and iv | 4. | i and iv |
Consider the given statements:
| I. | Gemmules are asexual reproductive structures in sponges. |
| II. | In Bryophyllum, vegetative propagation takes place by leaf buds. |
| III. | Marchantia is monoecious and Chara is dioecious. |
The correct statements are:
| 1. | Only I and II | 2. | Only I and III |
| 3. | Only II and III | 4. | I, II, and III |
Grafting is not successful in monocots but is successful in dicots because they have:
1. Vascular bundles arranged in a ring
2. Cambium for secondary growth
3. Vessels with elements arranged end to end
4. Cork cambium
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