Question

Select the incorrect statement regarding the vascular system of a cockroach:

• A. Heart is located along the mid-dorsal line of abdomen and thorax.
• B. They have well developed blood vessels
• C. Haemolymph is colorless
• D. Blood enters ostia via sinuses

Answer 1

The correct option is B They have well developed blood vessels

Cockroaches have an open type of blood vascular system. Blood vessels are poorly developed and open into haemocoel (an open space inside the body filled with blood). Blood of cockroach is colourless and is called haemolymph. The heart lies along the mid dorsal line of thorax & abdomen. The blood enters the ostia of heart via sinuses (haemocoel is divided into three sinuses) and is pumped back again into sinuses. There are 3 types of sinuses:
i. Pericardial sinus encloses heart
ii. Perivisceral sinus encloses visceral organs
iii. Perineural sinus encloses nerve cord