Which if these statements about hermaphroditic animals is false?

Answer 1

In my experience, people often think that hermaphroditic animals do not outcross (mate with other individuals), since they have both male and female reproductive organs. However, many hermaphroditic animals (and plants too) have mechanisms to promote outcrossing, while still allowing the occasional self fertilization when a mate cannot be found. For example, when earthworms (which are hermaphroditic) encounter another earthworm that is ready to mate, they line up their reproductive organs so that male is matched to female for each of the two worms. They then exchange gametes (each worm provides sperm for the other worm). So, even though they have both male and female organs, they are able to mate with other worms. Another example is in the plant world (I know you didn't ask, but plants are my specialty). Many plants have both male and female parts in their flowers, but can be self-incompatible, where pollen from the same plant cannot fertilize the egg because it is prevented from moving down the female plant tissue (style) by a genetic self-incompatibility system. So,even though these plants have both male and female organs (are hermaphroditic), they never self-fertilize and only outcross. Other hermaphroditic plants without the self-incompatibility system have ways of promoting outcrossing, by separating male and female function in space or time.