A married couple has 10 children and they are all girls. Which of the following is the CORRECT explanation?
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Correct Answer: Option E
Explanation:
The correct answer is E. The X component of the man’s sex chromosomes was always involved.
Here's why:
- In humans, the sex of a child is determined by the combination of sex chromosomes inherited from both parents.
- Women have two X chromosomes (XX), and men have one X and one Y chromosome (XY).
- A daughter inherits one X chromosome from both parents, so the mother will always contribute an X chromosome, while the father can contribute either an X or a Y chromosome.
- If the father always contributes an X chromosome, the result will always be a daughter (XX).
Since the couple in question has only daughters, it suggests that the father is consistently contributing the X chromosome, which means his sperm is carrying only X chromosomes and not Y chromosomes. Therefore, the X component of the man’s sex chromosomes was always involved, leading to the birth of only female children.
The correct answer is E. The X component of the man’s sex chromosomes was always involved.
Here's why:
- In humans, the sex of a child is determined by the combination of sex chromosomes inherited from both parents.
- Women have two X chromosomes (XX), and men have one X and one Y chromosome (XY).
- A daughter inherits one X chromosome from both parents, so the mother will always contribute an X chromosome, while the father can contribute either an X or a Y chromosome.
- If the father always contributes an X chromosome, the result will always be a daughter (XX).
Since the couple in question has only daughters, it suggests that the father is consistently contributing the X chromosome, which means his sperm is carrying only X chromosomes and not Y chromosomes. Therefore, the X component of the man’s sex chromosomes was always involved, leading to the birth of only female children.