AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
The basic filtration unit of the kidney is called the nephron. Each kidney contains a large number of nephrons packed close together.
Source: Life Processes, Section 5.5.1
The examiner expects the term nephron — this single word (with a brief supporting statement) is sufficient for 1 mark. Avoid lengthy descriptions of nephron structure here; that is asked in a separate 5-mark question. Just naming it correctly, perhaps with the note that kidneys contain many nephrons, is enough.