Pollen grains of water-pollinated species are protected by:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Mucilaginous covering
Explanation: In most of the water-pollinated species, pollen grains are protected from wetting by a mucilaginous covering.
The tallest flower Amorphophallus is about:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: 6 feet
Explanation: The tallest flower of Amorphophallus (the flower itself is about 6 feet in height).
In the Yucca-moth relationship, the moth deposits eggs in the:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Locule of ovary
Explanation: The moth deposits its eggs in the locule of the ovary.
Inbreeding depression is caused by:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Continued self-pollination
Explanation: Continued self-pollination result in inbreeding depression.
Self-incompatibility is a mechanism that 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.
If a plant is dioecious (like papaya), it prevents:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Both autogamy and geitonogamy
Explanation: In several species such as papaya... This condition prevents both autogamy and geitonogamy.
The central cell of the embryo sac becomes the:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Primary Endosperm Cell (PEC)
Explanation: The central cell after triple fusion becomes the primary endosperm cell (PEC).
Coconut water is an example of:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Free-nuclear endosperm
Explanation: The coconut water... is nothing but free-nuclear endosperm.
The cylindrical portion below the cotyledons in a dicot embryo is:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Hypocotyl
Explanation: The cylindrical portion below the level of cotyledons is hypocotyl.
In monocot embryos, the root cap is enclosed in:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Coleorrhiza
Explanation: The radical and root cap enclosed in an undifferentiated sheath called coleorrhiza.