Which of the following features is not present in Periplaneta americana?
Answer: (B) Indeterminate and radial cleavage during embryonic development. Answer: Indeterminate and radial cleavage is not seen in the cockroach.
- A.Schizocoelom as body cavity
- B.Indeterminate and radial cleavage during embryonic development✓
- C.Exoskeleton composed of N-acetylglucosamine
- D.Metamerically segmented body
Correct Answer
(B) Indeterminate and radial cleavage during embryonic development
Solution & Explanation
Answer: Indeterminate and radial cleavage is not seen in the cockroach. Solution: Periplaneta is an arthropod and, like other protostomes, shows determinate and spiral cleavage, not indeterminate radial cleavage (the latter is a deuterostome feature). It does have a schizocoelom, a chitinous exoskeleton (chitin is a polymer of N-acetylglucosamine) and a segmented body. The cleavage detail is extension content beyond Ch4 prose; NCERT lists arthropods as segmented coelomate animals with chitinous exoskeleton. NCERT Reference: Page 44, lines 9-12 (Arthropoda: segmented, coelomate, chitinous exoskeleton)