Question

Give scientific reason for the following statements:
i) Colour blindness is more common in men than in women.
ii) Blood flows in arteries in spurts and is under pressure.​

Answer 1

Answer-

1. Colour blindness is more common in men than in women.

• Colour blindness is more common in men than in women because it it is an X-linked recessive disorder. Men have just one X- chromosome and if that single X- chromosome has the allele for colour blindness, it gets expressed while in women there are 2 copies of X-chromosome in which defective allele of X-chromosome get masked by the effects of other X-chromosome.

2. Blood flows in arteries in spurts and is under pressure.

• As the ventricles of the heart contract, they push blood into the small lunen of the arteries with a great force, thus making the blood in arteries flow in spurts and under pressure.

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