Consider the following statements regarding geitonogamy:
1. It is the transfer of pollen to a different flower on the same plant.
2. It is functionally cross-pollination requiring an agent.
3. It is genetically similar to autogamy.
4. It introduces genetic variation in the offspring.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: 1, 2 and 3
Explanation: Statement 1 is correct.
Statement 2 is correct.
Statement 3 is correct (pollen from same plant).
Statement 4 is incorrect: Being genetically autogamous, it does not introduce variation.
Consider the following statements regarding wind pollination:
1. Pollen grains are light and sticky.
2. Stigma is often large and feathery to trap pollen.
3. Flowers are packed into inflorescences (e.g., Corn cob).
4. It is quite common in grasses.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: 2, 3 and 4
Explanation: Statement 1 is incorrect: Pollen must be non-sticky for wind transport.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is correct.
Consider the following statements regarding pollination in Vallisneria:
1. The female flower reaches the water surface by a long stalk.
2. Pollen grains are released into the water currents.
3. Pollination takes place on the surface of the water.
4. Female flowers remain submerged underwater.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: 1, 2 and 3
Explanation: Statement 1 is correct.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is incorrect: This describes seagrasses like Zostera, not Vallisneria.
Consider the following statements regarding seagrasses like Zostera:
1. Female flowers remain submerged in water.
2. Pollen grains are released inside the water.
3. Pollen grains are long and ribbon-like.
4. Pollen grains are covered by a mucilaginous coating.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: D
Answer: 1, 2, 3 and 4
Explanation: All statements are correct descriptions of pollination in seagrasses.
Consider the following statements regarding the Yucca plant and moth:
1. They have an obligate relationship.
2. The moth deposits eggs in the style of the flower.
3. The moth pollinates the flower.
4. The larvae emerge as the seeds start developing.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: 1, 3 and 4
Explanation: Statement 1 is correct.
Statement 2 is incorrect: Eggs are deposited in the locule of the ovary.
Statement 3 is correct.
Statement 4 is correct.
Consider the following statements regarding self-incompatibility:
1. It is a device to encourage self-pollination.
2. It is a genetic mechanism.
3. It prevents self-pollen from fertilising the ovules.
4. It works by inhibiting pollen germination or tube growth.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: 2, 3 and 4
Explanation: Statement 1 is incorrect: It is an outbreeding device to prevent self-pollination.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is correct.
Consider the following statements regarding pollen-pistil interaction:
1. The pistil rejects incompatible pollen.
2. Acceptance or rejection is mediated by chemical components.
3. Compatible pollen germinates on the stigma.
4. The pollen tube enters the ovule through the chalaza.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: 1, 2 and 3
Explanation: Statement 1 is correct.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is incorrect: It enters through the micropyle.
Consider the following statements regarding artificial hybridisation:
1. Emasculation is the removal of anthers from bisexual flowers.
2. It is done to prevent self-pollination.
3. Bagging protects the stigma from unwanted pollen.
4. Emasculation is always required for unisexual female flowers.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: 1, 2 and 3
Explanation: Statement 1 is correct.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is incorrect: Unisexual female flowers do not need emasculation.
Consider the following statements regarding double fertilisation:
1. Syngamy results in a diploid zygote.
2. Triple fusion results in a diploid Primary Endosperm Nucleus (PEN).
3. It involves the fusion of one male gamete with the egg and another with polar nuclei.
4. It is unique to flowering plants.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: 1, 3 and 4
Explanation: Statement 1 is correct.
Statement 2 is incorrect: PEN is triploid (3n).
Statement 3 is correct.
Statement 4 is correct.
Consider the following statements regarding post-fertilisation structures:
1. The central cell becomes the Primary Endosperm Cell (PEC).
2. The PEC develops into the endosperm.
3. The zygote develops into the embryo.
4. The PEN develops into the seed coat.
Which of the above statements are correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: 1, 2 and 3
Explanation: Statement 1 is correct.
Statement 2 is correct.
Statement 3 is correct.
Statement 4 is incorrect: PEN develops into endosperm nuclei; Integuments form seed coat.