Question

In which of the following organisms, self-fertilization can be seen?
A. Fish
B. Roundworm
C. Earthworm
D. Liver fluke

Answer 1

Hint: Self-fertilization is also known as the ‘Autogamy’ which refers to the fusion of the two gametes which are present in one parent or organism. It is also known as ‘selfing’.

Complete answer:
The process of self-fertilization can be seen in Live fluke. Self-fertilization is well known to be the fusion of gametes of both male and female in a similar individual. This type of fertilization occurs in bisexual organisms where both the gametes are present in the body of a single individual. It includes numerous protozoans, flowering plants and numerous invertebrates as well. Fertilization is internal in case of a Liver fluke. They are parasites of the liver of various mammals including humans.
i. The earthworms are hermaphrodites. They produce egg and sperm in the same body. But they cannot reproduce by the mode of self-fertilization. The reason behind this is that the male and female sex organs have different maturity time.
ii. Hermaphroditism is not reported in fishes, but self-fertilization does occur but it is also rare; among all vertebrate animals. Roundworm species reproducing the self-fertilization instead of fertilizing with the males have a very short lifespan.
Hence, the correct answer is option (D).

Note: Self-fertilization may occur in humans as well. Humans have both eggs and sperms in their body at fertilization, one sperm cell fuses with the egg to form a zygote which further develops in the embryo. Since the sperm contains a Y chromosome, this fertilization develops to an XY male embryo.