Practice question

Answer: C) Ammonia. For Excretory System, once you lock onto the key mechanism or definition, Ammonia is the clear fit. If you restate the concept in your own words, the functional job described in the stem is exactly what Ammonia does in Excretory System. So Ammonia is the clean, accurate selection. If a similar stem appears later, start from the same core fact and you will land on the same kind of answer. In class notes, highlight this same phrase next to the related diagram so the wording and the picture reinforce each other. When you practise, cover the choices first, write Ammonia from memory, then reveal the letter — that habit builds real recall for Excretory System.