Double Fertilisation

Correct Answer:

Insects or wind

Explanation:

Though water hyacinth and water lily are aquatic plants, pollination is not usually carried out by water (hydrophily) in these species. Instead:

• Water lily has large, attractive flowers which are often pollinated by insects such as beetles.
• Water hyacinth also relies on insects or wind for pollination, as its flowers emerge above the surface of the water.

Therefore, insects or wind are the primary pollinating agents in these plants, not water.

During Xenogamy, pollen grains from one plant's anthers are transferred to the stigma of another plant, resulting in genetically distinct pollen grains during pollination.

In flowering plants, the male and female gametes are produced in the pollen grain and embryo sac respectively. However, these gametes are non-motile and need to be brought together for the fertilization process.

Complete answer:

The transfer of pollen grains to the pistil's stigma is called pollination. Pollination can be of two types self-pollination and cross-pollination.

In xenogamy, the pollen grains are transferred to the stigma of the different plants. This brings genetically distinct pollen grains to the stigma of the flower.

Thus, option A is the correct answer.

Note: Complete autogamy is uncommon as it needs synchrony of pollen and stigma at the same time. The main difference between Xenogamy and Allogamy is that Xenogamy transfers pollen grain from one flower's anther to the stigma of a genetically different flower of the same species. In allogamy, pollen grains are transferred from the anther of a flower to the stigma of another either in the same plant or a different plant of the same species.

Correct Answer: Option 4 – Insect pollinated plants

The question asks which type of plants typically have large, colourful, and fragrant flowers with nectar. These features are classic adaptations seen in insect pollinated plants, also known as entomophilous plants.

Insect pollination is a form of biotic pollination where insects such as bees, butterflies, moths, and beetles transfer pollen from one flower to another. To attract these pollinators, plants develop specific floral characteristics, including:

• Large petals to provide a visible target
• Bright colours (such as blue, yellow, or ultraviolet patterns) to lure insects
• Fragrance to attract pollinators from a distance
• Nectar as a reward to encourage repeated visits

These traits ensure effective pollination, which increases reproductive success and promotes cross-pollination, thus enhancing genetic diversity in plant species.

Explanation of Other Options:

Option 1 – Bird pollinated plants: These plants (ornithophilous) usually have bright red or orange tubular flowers, but they are not fragrant because birds have a poor sense of smell. Nectar is present, but visual cues dominate over scent.

Option 2 – Bat pollinated plants: These flowers are typically dull in colour (often white or cream), large, and produce copious amounts of nectar. They are open at night and have a musty or fruity odour to attract bats.

Option 3 – Wind pollinated plants: These are generally inconspicuous, small, and lack colour, fragrance, or nectar. They produce lightweight, dry pollen in large quantities and have feathery stigmas to capture airborne pollen.

Conclusion: Large, colourful, and fragrant flowers with nectar are hallmark features of insect-pollinated plants. These adaptations are crucial for attracting pollinators and ensuring successful pollination, which is a vital topic in plant reproductive biology, especially for NEET and other competitive biology exams.