Pollen grains are generally spherical and a prominent two-layered wall. The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. It can withstand high temperatures and strong acids and alkali.

Correct Option: D

Pollen grains are generally spherical and a prominent two-layered wall. The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. It can withstand high temperatures and strong acids and alkali.

There are different types of vectors involved in pollination. For example, Maize, mulberry → pollination by wind. Vallisneria → pollination through water (hydrophily). Cucumber → Bees are brought for the commercial plantings of cucumber.

Correct Option: D

There are different types of vectors involved in pollination. For example, Maize, mulberry → pollination by wind. Vallisneria → pollination through water (hydrophily). Cucumber → Bees are brought for the commercial plantings of cucumber.

Single Megaspore Mother Cell (MMC) with dense cytoplasm and a prominent nucleus gets differentiated from nucellus near the micropylar region. This Megaspore Mother Cell (MMC) undergoes meiosis to form ‘4’ haploid cells called megaspores and the process of formation is known as megasporogenesis.

Correct Option: A

Single Megaspore Mother Cell (MMC) with dense cytoplasm and a prominent nucleus gets differentiated from nucellus near the micropylar region. This Megaspore Mother Cell (MMC) undergoes meiosis to form ‘4’ haploid cells called megaspores and the process of formation is known as megasporogenesis.

Cleistogamous flowers do not expose their reproductive parts. Anthers and stigma lie close to each other. Pure autogamy occurs since there is no chance of cross-pollination. Cleistogamy is the most efficient floral adaptation for promoting self-pollination. E.g., Viola mirabilis and Oxalis autosella.

Correct Option: B

Cleistogamous flowers do not expose their reproductive parts. Anthers and stigma lie close to each other. Pure autogamy occurs since there is no chance of cross-pollination. Cleistogamy is the most efficient floral adaptation for promoting self-pollination. E.g., Viola mirabilis and Oxalis autosella.

Sporogenous tissue is always diploid, endothecium is second layer of anther wall and perform the function of protection and help in dehiscence of anther to release the pollen. Hard outer layer of pollen is called exine but tapetum always nourishes the developing pollen. Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus (polypoid).

Correct Option: C

Sporogenous tissue is always diploid, endothecium is second layer of anther wall and perform the function of protection and help in dehiscence of anther to release the pollen. Hard outer layer of pollen is called exine but tapetum always nourishes the developing pollen. Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus (polypoid).