Which of the following diseases is much less common in women than in men?

Correct option is D

The correct answer is (d) Color blindness

Explanation:

• Color blindness (specifically red-green color blindness) is a sex-linked recessive disorder.

• The genes responsible for this condition are located on the X chromosome.

• Men have only one X chromosome ($XY$), so if they inherit the defective gene, they will manifest the condition.

• Women have two X chromosomes ($XX$); for a woman to be color blind, she must inherit the defective gene from both parents.

• If a woman has only one defective gene, she becomes a carrier but usually has normal vision.

• According to NCERT Class 12 Biology, color blindness affects approximately 8% of males and only about 0.4% of females.

Information Booster:

• The most common form of color blindness is the inability to distinguish between red and green colors.

• This occurs due to a mutation in certain genes that lead to the failure of one or more types of cone cells in the retina to respond to light.

Additional Knowledge:

Myopia (Option a)

• Also known as nearsightedness, this is a common vision condition where near objects appear clear but far objects are blurry.

• It is caused by the elongation of the eyeball or excessive curvature of the lens and does not show a significant sex-linked bias like color blindness.

Kidney stone (Option b)

• These are hard deposits of minerals and salts that form inside the kidneys.

• While historically more common in men, the gap has been narrowing in recent years due to changes in diet and lifestyle; however, it is not a genetic sex-linked disorder.

Brain tumor (Option c)

• This refers to an abnormal growth of cells in the brain.

• The incidence varies by the specific type of tumor (some are slightly more common in men, others in women), but they are not characterized by the drastic gender disparity seen in X-linked genetic traits.