Question

Dugesia shows
A) Transverse binary fission
B) Longitudinal binary fission
C) Oblique binary fission
D) No binary fission

Answer 1

Fission is a method of asexual reproduction. Asexual reproduction is a type of reproduction where only single parent gives rises to offspring. There is no involvement of opposite sexes in this type of reproduction.

Complete answer:
Transverse binary fission
It is a mode of asexual reproduction. In transverse binary fission, the cytoplasm separates transversely.This division divides single parents into two equal halves. Example- in ciliated protozoans like Paramecium.
Longitudinal binary fission
In longitudinal binary fission the cytoplasm separates along the longitudinal axis forming two daughter cells. Example- in flagellates like Euglena.
Oblique binary fission
In oblique binary fission the cytoplasm separates obliquely. Example- Ceratium.

Type of division in Dugesia:-

Dugesia is a genus representing flatworms.
They are hermaphrodites.
They reproduce by the means of asexual as well as sexual reproduction reproduction.
Usually they are reproduced by transverse binary fission.
Fission occurs when the animals get matured in order to reproduce.
After attaining maturity, the animal ruptures behind the pharynx.
Each ruptured part regenerates its missing parts and becomes a new individual.
So, from the above discussion it is clear that Dugesia shows transverse binary fission.

Hence, option A is the correct answer.

Note:Dugesia is a flatworm and we all know that flatworms have regeneration power. So it can regenerate its missing body parts easily and become a full new individual. And one more important thing is that they only reproduce when they attain their maturity.