Question

Which of the following is not present in Periplaneta americana?

• A. Schizocoelom as body cavity
• B. Indeterminate and radial cleavage during embryonic development
• C. Exoskeleton composed of N-acetylglucosamine
• D. Metamerically segmented body

Answer 1

The correct option is B Indeterminate and radial cleavage during embryonic development

The body of Periplaneta americana is metamerically segmented and is divided into head, thorax and abdomen. The entire body is covered by a hard chitinuous exoskeleton which is composed of N-acetylglucosamine.
Cockroach is a eucoelomate. True eucoelomates is of two types; schizocoelom (schizocoel) and enterocoelom (enterocoel).
Schizocoelom - It develops as a split in the mesoderm sheet. It is found in annelids, arthropods (cockroach), molluscs.
Cleavage is the division of cells in an early embryo. It is of two types- Determinate and Indeterminate.
Indeterminate cleavage is the division of an egg into cells, each of which has the potential of developing into a complete organism.
Determinate cleavage is the division of an egg into cells, each of which does not have the capacity to develop into a complete organism.
Cockroach has determinate cleavage during embryonic development and it develops into nymph, which is a fully developed cockroach