Assertion (A): In human beings, the females play a major role in determining the sex of the offspring. Reason (R): Women have two ‘X’ chromosomes.Codes:
✓ Correct answer: d) A is false but R is true
ExplanationAssertion (A) is false: Humans have 46 chromosomes (23 pairs), one of which determines sex.This pair consists of XX in females and XY in males.During reproduction, the mother always contributes an X chromosome, while the father can contribute either an X or a Y chromosome.If a sperm carrying an X chromosome fertilizes the egg, the offspring will be female (XX), whereas if a sperm carrying a Y chromosome fertilizes the egg, the offspring will be male (XY).Since the sperm determines the final chromosomal combination, the father plays the major role in sex determination.Reason (R) is true: Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).481
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