Question

Female Ascaris is differentiated from male by having-
a. Cloaca
b. Penial setae
c. Shorter size
d. Straight posterior end

Answer 1

Hint: Ascaris is a nematode. It is a parasite of the human intestine and causes a disease called ascariasis. The Ascaris females have a straight posterior end while the male Ascaris bear bent posterior end.

Complete answer:
> Ascaris are the intestinal roundworms. The male and female Ascaris may appear similar but there are several distinguishable characters which differentiates the two sexes. There are many external features that occur and can be used to differentiate the male and female. Externally, the two sexes can be differentiated by their body size and presence and absence of certain morphological characters. The female Ascaris are larger in size as compared to the males.

> The female Ascaris has a straight blunt tail or posterior end while the male Ascaris does not have any straight tail rather they are slightly coiled or appear hooked at the posterior end.

> The male Ascaris are much shorter in length as compared to the female.

> The cloaca or penial setae is present in the case of Ascaris male. These are absent in females. The penial setae and cloaca are the important organs used during the process of reproduction in Ascaris. The female lacks such organs.

> The female Ascaris will have a reproductive opening on the posterior third of its body while males lack any such openings.

Hence, the option d) straight posterior end option is correct.

Note: There are many differences among the male and female of Ascaris as they show the differences mainly depending on their external characteristics or morphological features. The general differences in the morphological features are done based on the common species of Ascaris, which is Ascaris lumbricoides.