Question

Roundworms differ from flatworms in having _______.

• A. flame cells
• B. pseudocoel
• C. segmented body
• D. flagella

Answer 1

Answer: (A), (B)

pseudocoel

The correct options are A and B.

Explanation of correct options:

1. Flatworms belong to the phylum Platyhelminthes whereas roundworms belong to the phylum Nematoda.
2. Flatworms are acoelomate whereas roundworms contain pseudocoel.
3. Flame cells are present in flatworms whereas renette cells are present in roundworms.

Explanation of incorrect options:

Option C:

1. Flatworms and roundworms both have an unsegmented body with an anterior end and posterior end.

Option D:

1. Flatworms and roundworms both have cilia for locomotion.

Final answer: Roundworms differ from flatworms in having flame cells and pseudocoel.