Flowers pollinated by flies and beetles are distinct because they:

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Produce abundant sweet nectar.
• Are brightly colored and odorless.
• Secrete foul odours to attract these animals.
• Have long floral tubes.

Which floral reward does the tall flower of Amorphophallus provide to its pollinator?

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Edible pollen.
• Large amounts of nectar.
• A safe place to lay eggs.
• Resins and gums.

The obligate relationship between the Yucca plant and a species of moth involves:

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• The moth eating the leaves and pollinating the flower.
• The moth depositing eggs in the ovary locule and pollinating the flower.
• The moth using the stem for shelter.
• The plant trapping the moth to digest it.

Which of the following is NOT an outbreeding device used by plants to prevent self-pollination?

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Self-incompatibility.
• Dicliny (production of unisexual flowers).
• Synchronization of pollen release and stigma receptivity.
• Placement of anther and stigma at different positions.

Monoecious plants like castor and maize prevent which type of pollination?

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Autogamy but not geitonogamy.
• Geitonogamy but not autogamy.
• Both autogamy and geitonogamy.
• Neither autogamy nor geitonogamy.

Dioecious plants like papaya prevent:

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Only autogamy.
• Only geitonogamy.
• Both autogamy and geitonogamy.
• Xenogamy.

Pollen-pistil interaction is a dynamic process that involves:

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Only physical adherence of pollen to stigma.
• Chemical dialogue allowing recognition of compatible pollen.
• Immediate germination of any pollen grain landing on stigma.
• Digestion of the stigma by pollen enzymes.

In plants where pollen is shed at the 2-celled stage, when does the generative cell divide to form male gametes?

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• Before pollen is shed from the anther.
• On the stigma before germination.
• During the growth of the pollen tube in the stigma/style.
• Inside the embryo sac.

What is the purpose of "emasculation" in artificial hybridization techniques?

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• To remove the stigma to prevent pollination.
• To remove anthers from bisexual flowers to prevent self-pollination.
• To cover the flower with a bag.
• To introduce foreign pollen.

Triple fusion in the angiosperm embryo sac involves the fusion of:

[Sexual-Reproduction-in-Flowering-Plants] [class-xii]

• One male gamete with the egg cell.
• One male gamete with two polar nuclei.
• Two male gametes with the central cell.
• The tube nucleus with the polar nuclei.