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.
- ABoth A and R are true, and R is the correct explanation of A
- BBoth A and R are true, but R is not a correct explanation of A
- CA is true, but R is false
- DA is false, but R is trueCorrect
Explanation
The assertion is false because in human beings, the male determines the sex of the offspring. Females possess two X chromosomes and can only contribute an X chromosome to the child. Males possess one X and one Y chromosome. If a sperm carrying an X chromosome fertilizes the egg, the offspring will be female. If a sperm carrying a Y chromosome fertilizes the egg, the offspring will be male. Therefore, the sex of the child depends entirely on the father. The reason is true because women do indeed have two X chromosomes, but this fact explains why they do not have a role in sex determination rather than supporting the assertion. Since the assertion is false and the reason is true, option D is the correct answer.
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