Question

Match List I with List II 

Choose the correct answer from the options given below: 
 

• A. A-III, B-I, C-IV, D-II
• B. A-I, B-III, C-IV, D-II
• C. A-II, B-IV, C-III, D-I
• D. A-III, B-I, C-II, D-IV

Hint:

Metabolic defects (like Alkaptonuria) usually show up at birth.
Structural traits (like Blood groups) show up before birth.
Sex-influenced traits (like Baldness) show up after maturity.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks to match specific human genetic traits or diseases with the typical life stage at which their phenotype first becomes detectable (onset of expression).

Step 2: Detailed Explanation:

• Blood Groups (B-I): ABO and Rh blood group antigens are synthesized by the fetus and are present on red blood cells before birth. They can be detected in prenatal stages or cord blood.

• Alkaptonuria (A-III): This is an inborn error of metabolism where homogentisic acid is excreted in urine. The phenotype (darkening of urine when exposed to air) is observable immediately after birth (often noticed on diapers).

• Rickets (D-II): This is a bone disorder (often due to Vitamin D deficiency or genetics). It typically manifests once the child starts bearing weight and growing rapidly, usually showing clinical signs about 1 year after birth (bowing of legs).

• Baldness (C-IV): Pattern baldness is a sex-influenced trait. While the genotype is present at birth, the expression requires the influence of hormones (androgens) that reach peak levels after puberty. Onset is usually in young adulthood, about 20-25 years after birth.
Final Answer:
Matching: A-III, B-I, C-IV, D-II.
This corresponds to option (A).