Q141 (2024)
Match List I with List II related to embryonic development at various months of pregnancy:
<div style="overflow-x: auto; margin: 1rem 0;"><table style="width: 100%; border-collapse: collapse; text-align: left; font-size: 14px;"><thead><tr><th style="border: 1px solid #888; padding: 8px;">List-I</th><th style="border: 1px solid #888; padding: 8px;">List-II</th></tr></thead><tbody><tr><td style="border: 1px solid #888; padding: 8px;">(A) The foetus movement starts and hair appears on the head</td><td style="border: 1px solid #888; padding: 8px;">(I) 24 weeks of pregnancy</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">(B) The foetus develops limbs and digits</td><td style="border: 1px solid #888; padding: 8px;">(II) 20 weeks of pregnancy</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">(C) The foetus develops external genital organs</td><td style="border: 1px solid #888; padding: 8px;">(III) 8 weeks of pregnancy</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">(D) The foetus body is covered with fine hair; eyelids separate and eyelashes are formed</td><td style="border: 1px solid #888; padding: 8px;">(IV) 12 weeks of pregnancy</td></tr></tbody></table></div>
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Choose the correct answer from the options given below:
- A-III, B-II, C-IV, D-I
- A-II, B-IV, C-III, D-I
- A-IV, B-II, C-III, D-I
- A-II, B-III, C-IV, D-I
### Related Formula
$\text{Foetal Development Timeline:}
\begin{aligned}
\text{8 weeks (2 months)} &\rightarrow \text{Limbs and digits}\\
\text{12 weeks (1st trimester)} &\rightarrow \text{External genital organs}\\
\text{20 weeks (5th month)} &\rightarrow \text{First movement and hair on head}\\
\text{24 weeks (2nd trimester)} &\rightarrow \text{Fine hair, eyelids separate, eyelashes}
\end{aligned}$
### Core Logic
Matching each milestone with gestation period:
* (A) First movement and head hair $\rightarrow$ 5th month / 20 weeks (II)
* (B) Limbs and digits $\rightarrow$ 2nd month / 8 weeks (III)
* (C) External genital organs $\rightarrow$ 12 weeks / end of 1st trimester (IV)
* (D) Body fine hair, eyelids separate $\rightarrow$ 24 weeks / end of 2nd trimester (I)
### Step 1: Final Combination
The correct mapping is A-II, B-III, C-IV, D-I.
### Pattern Recognition
Sees: "foetus movement hair head".
Shortcut: Movement/head hair = 5th month (20 weeks). Eye lashes/separated eyelids = 24 weeks.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Biology: Human Reproduction
