Question

Match List - I with List - II. 

Choose the correct answer from the options given below : 
 

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

Hint:

If you are given a 3-letter genetic code containing 'T', it is DNA. If the question doesn't specify which strand it is, assume it's the Template strand, swap T for A, A for U, C for G, and check if it makes a recognized mRNA codon. Tryptophan is a great anchor point because it only has one single codon: UGG.

Answer 1

The Correct Option is C

Step 1: Concept:
The question asks to match specific amino acids (List I) with base triplets (List II). Notice that List II contains the base Thymine (T), indicating these are DNA sequences, not mRNA codons. Specifically, these are the triplet sequences on the template (non-coding) strand of DNA reading $3' \rightarrow 5'$.

Step 2: Step-by-step Explanation:
To solve this, we must first transcribe the template DNA triplets into mRNA codons ($5' \rightarrow 3'$) using standard base-pairing rules (G$\leftrightarrow$C, T$\rightarrow$A, A$\rightarrow$U). Then we map the mRNA codon to its corresponding amino acid using the genetic code dictionary.

• I. GTA:
Template DNA: 3'-GTA-5'
mRNA Codon: 5'-CAU-3'
Amino Acid: Histidine. (C $\rightarrow$ I)

• II. ACC:
Template DNA: 3'-ACC-5'
mRNA Codon: 5'-UGG-3'
Amino Acid: Tryptophan. (D $\rightarrow$ II)

• III. TGC:
Template DNA: 3'-TGC-5'
mRNA Codon: 5'-ACG-3'
Amino Acid: Threonine. (A $\rightarrow$ III)

• IV. GAT:
Template DNA: 3'-GAT-5'
mRNA Codon: 5'-CUA-3'
Amino Acid: Leucine. (B $\rightarrow$ IV)
The complete matching sequence is A-III, B-IV, C-I, D-II.

Step 3: Final Answer:
The correct matching sequence aligns exactly with option (C).