Question

Select the correct statement from the ones given below with respect to Periplaneta americana

• A. Nervous system located dorsally consists of segmentally arranged ganglia joined by a pair of longitudinal connectives
• B. Males bear a pair of short thread like anal styles
• C. There are 16 very long malpighian tubules present at the junctions of midgut and hindgut
• D. Grinding of food is carried out only by the mouth parts.

Answer 1

Answer: (B)

1. The nervous system of cockroach consists of a series of fused, segmentally arranged ganglia joined by paired longitudinal connectives on the ventral side.
2. Males bear a pair of short, threadlike anal styles which are absent in females.
3. At the junction of midgut and hindgut a ring of 100-150 thin filamentous Malpighian tubules are present. They help in removal of excretory products from haemolymph.
4. Apart from mouth, grinding of food is also performed by gizzard or proventriculus. It has an outer layer of thick circular muscles and thick inner culicle forming six highly chitinous plate called teeth.

So, the correct option is 'Males bear a pair of short thread like anal styles'.