How are Water Hyacinth and Water Lily pollinated?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: By insects or wind
Explanation: In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind as in most of the land plants.
The tallest flower, Amorphophallus, provides which specific reward to its pollinator?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Safe place to lay eggs
Explanation: In some species floral rewards are in providing safe places to lay eggs; an example is that of the tallest flower of Amorphophallus.
Continued self-pollination in hermaphrodite flowers often leads to:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Inbreeding depression
Explanation: Continued self-pollination result in inbreeding depression.
Self-incompatibility is a mechanism that prevents self-pollination. It is:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Genetic
Explanation: The third device to prevent inbreeding is self-incompatibility. This is a genetic mechanism.
Which of the following conditions prevents both autogamy and geitonogamy?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Dioecy (e.g., Papaya)
Explanation: In several species such as papaya, male and female flowers are present on different plants... (dioecy). This condition prevents both autogamy and geitonogamy.
Pollen-pistil interaction involves recognition mediated by:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Chemical components
Explanation: This dialogue is mediated by chemical components of the pollen interacting with those of the pistil.
Emasculation is the removal of anthers from a flower bud. It is performed to:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Prevent self-pollination in bisexual flowers
Explanation: If the female parent bears bisexual flowers, removal of anthers... is referred to as emasculation... to prevent contamination of its stigma with unwanted pollen (essentially self-pollen in this context).
Double fertilisation consists of which two events?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Syngamy and Triple Fusion
Explanation: Since two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilisation.
Which of the following seeds is albuminous (retains endosperm)?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Castor
Explanation: Albuminous seeds retain a part of endosperm... e.g., wheat, maize, barley, castor.
Seeds that have no residual endosperm as it is consumed during embryo development are called:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Non-albuminous
Explanation: Non-albuminous seeds have no residual endosperm as it is completely consumed during embryo development (e.g., pea, groundnut).