Question

Where does the Nitrogenous waste in the Malpighian tubule of cockroach pass into?
A) Haemocoel
B) Intestine
C) Vacuole
D) Duodenum

Answer 1

Malpighian tubules of insects and other terrestrial arthropods remove nitrogenous wastes and other solutes from the haemolymph. $Na^+$ and/or $K^+$ ions are actively transported into the lumen of the tubules.

Complete answer:

1. Haemocoel is the body cavity of cockroaches is not a true coelom but a haemocoel containing blood (hemolymph). Insects do not possess an arrangement of blood vessels such as those in mammals. Instead insects have this cavity that is full of insect blood) and the organs of the insect are suspended in this cavity.
2. The intestines in cockroaches together comprise the hindgut. The hindgut has three main parts: Ileum which is a small, narrow, tabular part. It absorbs the remaining nutrients; Colon which is a highly coiled structure, and rectum which is the broad last part of the hindgut and stores undigested food for some time. Malpighian tubules remove wastes and actively transport them into the lumen of the tubules. Water then enters the tubules via osmosis, forming urine. The urine passes through the intestine, and into the rectum.
3. Vacuoles:- In the epicuticle of the cockroach there is a cement layer formed, by secretion from certain of the dermal glands at the time of moulting. These dermal glands are widely distributed over the abdominal tergites and sternites in both sexes. Their cell-bodies are atrophied in the mature insect. They differ in this respect from the very numerous dermal glands on the abdominal tergites of the male, which remain distended with vacuoles.
4. The distal part of duodenum is part of the foregut.

Thus, the correct answer is option B (Intestine).

Note: The Malpighian tubules are named after Marcello Malpighi, a seventeenth-century anatomist.The Malpighian tubules also secrete fluids within the posterior intestine where they are reabsorbed and certain substances are transported into the hemolymph.