Excretion of semi-solid nitrogenous waste is typical of:
Answer: C) Birds. For Excretory System, once you lock onto the key mechanism or definition, Birds is the clear fit. If you restate the concept in your own words, Birds is the option that correctly names the structure, process, or principle asked for in Excretory System. So Birds 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 Birds from memory, then reveal the letter — that habit builds real recall for Excretory System.
Ref: Animal physiology is Unit 7 of the CSIR NET Life Science Syllabus, covering core body systems. It accounts for roughly 10% of the total marks in Sections B and C.