Question

Match List I with List II related to embryonic development at various months of pregnancy:

List I                                                     List II
A. The foetus movement starts and hair appears on the head I. 24 weeks of pregnancy
B. The foetus develops limbs and digits                    II. 20 weeks of pregnancy
C. The foetus develops external genital organs             III. 8 weeks of pregnancy
D. The foetus body is covered with fine hair; eyelids 
   separate and eyelashes are formed                       IV. 12 weeks of pregnancy

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

Hint:

Logic Tip: A chronological timeline helps: 8 weeks (2 months) $\rightarrow$ Limbs and digits. 12 weeks (3 months/1st trimester) $\rightarrow$ Organ systems and genitals. 20 weeks (5 months) $\rightarrow$ First movement and head hair. 24 weeks (6 months/2nd trimester) $\rightarrow$ Body hair, eyelids separate.

Answer 1

The Correct Option is C

Concept:
Human gestation lasts about 9 months (or 40 weeks). Significant developmental milestones occur at specific intervals during embryonic and fetal development, which are important clinical markers for monitoring fetal health.
Step 1:
The first movements of the fetus (quickening) and the appearance of hair on the head are typically observed during the fifth month of pregnancy, which corresponds to roughly 20 weeks. Match: A $\rightarrow$ II
Step 2:
By the end of the second month of pregnancy (which is 8 weeks), the embryo rapidly differentiates, and the major structural features, including limbs and digits, are formed. Match: B $\rightarrow$ III
Step 3:
By the end of the first trimester (12 weeks or 3 months), most major organ systems are formed. For example, the limbs and external genital organs are well developed, making sex determination possible via ultrasound. Match: C $\rightarrow$ IV
Step 4:
By the end of the second trimester (24 weeks or 6 months), the body is covered with fine hair (lanugo), eyelids separate, and eyelashes are formed. Match: D $\rightarrow$ I
Step 5:
Combining the verified developmental milestones yields the sequence: A-II, B-III, C-IV, D-I. This perfectly matches Option (3).