Question

Codon bias is correlated with the relative frequencies of which one of the following types of RNA?

• A. ( mRNA )
• B. ( rRNA )
• C. ( siRNA )
• D. ( tRNA )

Hint:

When studying gene expression optimization in different organisms, examining tRNA gene copy numbers can provide insights into codon usage patterns and evolutionary adaptations to translational efficiency.

Answer 1

The Correct Option is D

Codon bias refers to the phenomenon where certain codons are used more frequently in the coding sequences of genes than others. This bias is closely linked to the availability and frequency of corresponding anti-codons in tRNA molecules. 
Analysis of Each Option: (A) mRNA: While mRNA contains codons, the concept of codon bias is not merely about their presence but rather their usage frequency, which is influenced by tRNA availability. 
(B) rRNA: Ribosomal RNA (rRNA) is involved in the structure and catalytic function of ribosomes and does not interact with mRNA codons in a way that influences codon bias. 
(C) siRNA: Small interfering RNA (siRNA) is involved in the RNA interference pathway and does not play a role in codon usage or bias. 
(D) Correct: tRNA molecules carry amino acids to the ribosome and pair with the codons in mRNA during translation. The availability of tRNA species corresponding to specific codons can influence the frequency of these codons in genes, thereby affecting codon bias. Conclusion:
Explanation: The correlation between codon bias and tRNA frequencies is crucial for understanding how genes are efficiently translated within cells. Organisms often optimize their gene expression by using codons that match the most abundant tRNAs, leading to more efficient protein synthesis.