AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
In snails, individuals can change their sex during their lifetime, which indicates that sex determination in snails is not genetically determined but depends on environmental or other non-genetic factors. In contrast, in human beings, sex is genetically determined — by the sex chromosomes (XX for female, XY for male) inherited from parents.
The key contrast examiners expect is: snails = non-genetic/environmental sex determination; humans = genetic sex determination via X and Y chromosomes. Mention both sides clearly for full 2 marks. The textbook explicitly states "individuals can change sex, indicating that sex is not genetically determined" — use this phrasing directly.
Source: Chapter 8, Section 8.2.4 Sex Determination