The junction between the ovule and the funicle is called:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Hilum
Explanation: The body of the ovule fuses with the funicle in the region called hilum. Thus, hilum represents the junction between ovule and funicle.
The method of embryo sac formation from a single megaspore is termed as:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Monosporic development
Explanation: Only the functional megaspore develops into the female gametophyte (embryo sac). This method of embryo sac formation from a single megaspore is termed monosporic development.
How many nuclei and cells are present in a typical mature angiosperm embryo sac?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: 8 nuclei, 7 cells
Explanation: A typical angiosperm embryo sac, at maturity, though 8-nucleate is 7-celled. It consists of an egg apparatus (3 cells), antipodals (3 cells), and a central cell (1 cell with 2 nuclei).
The cellular thickening at the micropylar tip of synergids that guides the pollen tube is called:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Filiform apparatus
Explanation: The synergids have special cellular thickenings at the micropylar tip called filiform apparatus, which play an important role in guiding the pollen tubes into the synergid.
Pollination which occurs within the same flower is termed:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Autogamy
Explanation: In this type, pollination is achieved within the same flower. Transfer of pollen grains from the anther to the stigma of the same flower is called autogamy.
Which of the following plants produces both chasmogamous and cleistogamous flowers?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Viola (Common pansy)
Explanation: Some plants such as Viola (common pansy), Oxalis, and Commelina produce two types of flowers: chasmogamous flowers and cleistogamous flowers.
What is the primary advantage of cleistogamy?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Assured seed-set even in absence of pollinators
Explanation: Cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma. They produce assured seed-set even in the absence of pollinators.
Transfer of pollen grains from the anther to the stigma of another flower of the same plant is called:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Geitonogamy
Explanation: Geitonogamy is the transfer of pollen grains from the anther to the stigma of another flower of the same plant. Genetically it is similar to autogamy.
Which type of pollination brings genetically different types of pollen grains to the stigma?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Xenogamy
Explanation: Xenogamy is the transfer of pollen grains from anther to the stigma of a different plant. This is the only type of pollination which brings genetically different types of pollen grains to the stigma.
Which of the following is a characteristic of wind-pollinated flowers?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: D
Answer: Feathery stigma and light pollen
Explanation: Wind pollination requires that pollen grains are light and non-sticky. The flowers often possess well-exposed stamens and large often-feathery stigma to trap air-borne pollen.