The waste product of insects is?

Step 1: Analyze the question The question asks about the main nitrogenous waste product of insects, which is a question about excretion.

Step 2: Explain the concept Insects excrete through Malpighian tubules, which are thin tubes attached to the gut between the midgut and hindgut. Here is how they work:

• They absorb nitrogenous waste from the haemolymph (insect blood).
• The waste is converted to uric acid, which is insoluble in water.
• The uric acid passes into the hindgut and leaves the body with the faeces.

Insects excrete uric acid because it needs very little water. This is an important adaptation for conserving water on land, which is why it is called a uricotelic strategy. Birds and reptiles do the same.

Step 3: Check each option

• A. Uric acid: Correct. It is the main nitrogenous waste of insects.
• B. Urine: Wrong. Insects have no kidneys, so they do not produce liquid urine like mammals do.
• C. Mucilage: Wrong. This is a sticky substance made by plants, not an insect waste product.
• D. Sweat: Wrong. Insects have no sweat glands. Sweating is a feature of mammals.

Step 4: Answer The correct option is A, uric acid.

Exam tip: Remember "Insects, Birds, Reptiles = Uric acid" (they save water). Mammals and amphibians excrete urea. Also remember "Malpighian tubules = insects", which is a favourite JAMB link.