Question

Given below are two statements:
Statement I: Genetic code consists of a linear series of nucleotide triplets
Statement II: Each triplet code is complementary to the information stored in DNA
In the light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is correct but Statement II is false
• D. Statement I is incorrect but Statement II is true

Hint:

Features of Genetic Code: 1. Triplet nature (3 nucleotides = 1 codon), 2. Linear and comma-less, 3. Non-overlapping, 4. Complementary to DNA template strand, 5. Degenerate and Universal.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Molecular nature of the genetic code: linear, non-overlapping, triplet codons in mRNA transcribed complementarily from the DNA non-coding template strand.
Key Formula or Approach:
\[ \text{DNA Template (3'-TAC-5')} \xrightarrow{\text{Transcription (Complementary)}} \text{mRNA Codon (5'-AUG-3')} \longrightarrow \text{Amino Acid (Methionine)} \]

Step 2: Detailed Explanation:
1. Statement I: The Genetic Code is organized as a contiguous, non-overlapping linear series of consecutive nucleotide triplets (codons) in messenger RNA (64 codons encoding 20 standard amino acids and 3 stop signals). Hence, Statement I is true.
2. Statement II: Each mRNA triplet codon is synthesized during transcription by RNA polymerase as an exact complementary ribonucleotide sequence to the base sequence stored in the template strand of genomic DNA (Watson-Crick base pairing: A-U, T-A, G-C, C-G). Hence, Statement II is true.

Step 3: Final Answer:
Thus, Both Statement I and Statement II are true, corresponding to option (A).