Which of the following is correct for the common cockroach ?

Options

A. Malpighian tubules are excretory organs projecting out from the colon
B. Oxygen is transported by haemoglobin in blood
C. Nitrogenous exretory product is urea
D. The food is grinded by mandibles and gizzard

Answer

D

Explanation

The two mandibles in the mouth part of cockroach bear teeth which cut and masticate the food into fine particles. Gizzard is part of alimentary canal which is used for grinding the food as it bears six muscular folds covered by chitinous conical plates, the teeth.