Question

What prevents self-fertilization in earthworm, even though it is a hermaphrodite?

Answer 1

Hint:Hermaphrodites are organisms that have both male and feminine reproductive organs. samples of these are sponges, sea anemones, tapeworms, snails, and earthworms. they're either sedentary or mobile but don't move around enough to permit them to self-fertilize. Which causes problems for reproduction and mating because they rarely meet their own species.

Complete answer:
An earthworm may be a terrestrial invertebrate that belongs to the Annelida. They exhibit a tube within a tube body plan and are externally segmented with corresponding internal segmentation, and typically have setae on all segments. They occur worldwide in soil, water, and appropriate temperature. The earthworms are hermaphrodites. They will produce eggs and sperm within the same body. they can't reproduce by self-fertilization. the reason is that the male and therefore the female sex organs don't mature at an equivalent time. When the male sex organs are matured, the feminine reproductive organ remains underdeveloped and both organs are present at the other end of the body so earthworm isn't ready to align its body for fertilization. Thus, the sperms which are released by the earthworms cannot fertilize the egg within the same earthworm. This prevents the method of self-fertilization.

Note:
Earthworms have a modified external fertilization. After copulating during which each hermaphroditic earthworm exchanges sperm with another, earthworms create a cocoon external to their clitellum. Eggs from their own ovaries and sperm from their mate are deposited into the cocoon during cocoon formation. Fertilization and development occur within the cocoon which is deposited within the soil. The ova or the eggs are fertilized by the sperm cells within the cocoon. which later slips off the worm and is deposited in or on the soil.