AP BIOLOGY

Detailed explanation-1: -The sperm needs to swim through water in order to get to the eggs. The eggs are housed or maintained in the gametophyte. And that dependence on water is why ferns are so often linked to wet habitats.

Detailed explanation-2: -The sperm must “swim” in a drop of water to an egg to fertilize it-which means that, with a few exceptions, water must be present for a fern to reproduce. Ideally, the sperm from one prothallus fertilizes the egg of another prothallus, thus mingling genetic material, but a fern can self-fertilize.

Detailed explanation-3: -Male and female reproductive structures develop on the lower surface of the same, or more often, on different gametophyte plants. At sexual maturity, the male structures release sperm that swim through the film of water of the moist habitat to fertilize the egg in the female structure.

Detailed explanation-4: -Both mosses and ferns produce sperms (male gametes produced by antheridia) that have flagella (hair-like appendage). This appendage provides motility to the sperm. Both these plants require water so that the sperms can swim in that to reach the archegonia (contains female gamete).

Detailed explanation-5: -Ferns do not flower but reproduce sexually from spores. There are two distinct stages of the fern life cycle. Mature plants produce spores on the underside of the leaves. When these germinate they grow into small heart-shaped plants known as prothalli.