Question

How can male and female Ascaris be identified?
A. Posterior end of the male is straight, while that of the female is curved
B. Anterior end of a female is curved, while that of a male is straight
C. Posterior end of the male is curved, while that of the female is straight
D. Anterior end of males is curved, while that of females is straight.

Answer 1

Hint: Ascaris belongs to Animal Kingdom Aschelminthes.
The female is larger and the male is smaller. They marked sexual dimorphism.
They are known as the giant intestinal roundworm. They occur in the small intestine.

Complete answer: Male ascaris: It is about 15 to 30 cm, hind end is curved.
The anus is an outlet for the digestive tracts, hence called the cloacal aperture.
There is no separate genital aperture.
Two penial spicules project from the cloacal aperture.
A cushion-like prominence occurs just in front of the cloacal aperture.
Female Ascaris: It is about 20 to 40 cm long, hind limb is straight.
The anus is an outlet for the digestive tract only.
There is a separate midventral genital aperture.

 So, the correct answer is “Option C. Posterior end of the male is curved, while that of the female is straight”.

Note: Ascaris(Ascaris lumbrcoides) hosts digested food. It respires anaerobically.
1. The life cycle is simple, there being no intermediate host and larval form.
2. It is holozoic and takes the host,s digested food by sucking. Ascaris is oviparous.
3. The life span Ascaris varies from 9 to 12 months.