Read the following statement regarding the excretory system of a cockroach and choose the option that correctly fills the blanks A, B, C, and D. In cockroach, excretion is primarily performed by __A__ which are present at the junction of __B__ and __C__, making the insect __D__.

Step-by-step solution

In cockroaches, the primary excretory organs are the Malpighian tubules (A). These are a ring of 100-150 yellow-coloured, thin filamentous structures located at the junction of the midgut (B) and hindgut (C). The Malpighian tubules absorb nitrogenous waste from the haemolymph and convert it into uric acid, which is excreted out through the hindgut. Because it excretes uric acid, the cockroach is a uricotelic (D) insect. Hepatic caeca are present at the junction of the foregut and midgut and are involved in secretin