Question

The female Ascaris can be distinguished from the male by
A.Curved posterior part of the body
B.Short posterior part of the body
C.Presence of pineal setae
D.Straight posterior part

Answer 1

Animals that belong to the phylum Aschelminthes are dioecious in nature. It means that sexes are separate in these animals. Females can be distinguished from the males by their morphological differences.

Complete step by step answer: In some animals, sexes are not separate. Male and female gametes are formed in the same individual in these animals and are called hermaphrodites. This phenomenon is called hermaphroditism. Hermaphrodites are also called monoecious as the sexes are not separate in these individuals. Know that they are also called bisexual animals. If separate sexes are seen in certain animals, they are called dioecious or unisexual animals.
Aschelminthes are also called roundworms as their body is circular in cross-section. These are bilaterally symmetrical worms that have a complete alimentary canal. Know that a well developed muscular pharynx is a feature of roundworms.
Females are easily distinguishable in these animals as the females are longer than males. Also, the posterior part of the female body is curved.
Pineal setae are seen only in male Ascaris. It is with the help of these morphological differences, we distinguish male and female Ascaris.
Hence the correct option is A.

Note: In some animals, male and female sex organs are seen in a single individual. The phenomenon of having both male and sex organs in the same individual is also called gonochorism. Male and female gametes are released from a single body and fertilization may take place either in the external environment as in ctenophores or inside the individual as in sponges and Platyhelminthes.