Question

The two organisms from the above picture are anatomically similar but, they belong to two different phylum. Why?

• A. Due to different type of coelom
• B. Due to presence of body segmentation
• C. Due to organ differentiation
• D. Due to difference in their habitat.

Answer 1

Answer: (A), (B), (C)

The correct options are
A Due to different type of coelom
B Due to presence of body segmentation
C Due to organ differentiation

$\bullet$ Earthworm is an annelid while roundworm is a nematode. They are anatomically similar.
$\bullet$ Annelids and nematodes are bilaterally symmetrical.
$\bullet$Annelids are the first organisms to show a true body cavity (coelom) whereas Nematodes have false coelom (pseudocoelom).
Annelids are different from nematodes as they have a segmented body with extensive organ differentiation. Thus, annelids are little more complex in body organisation than nematodes.