According to recent concept the number of types of t RNA is equal to

Options

A. No.of sense codons
B. No.of non sense codons
C. Total no. of triplet codons
D. No. of termination codons

Answer

To answer the question regarding the number of types of tRNA according to recent concepts, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding tRNA**: Transfer RNA (tRNA) is a type of RNA molecule that helps in the translation process during protein synthesis. Each tRNA molecule carries a specific amino acid and has an anticodon that is complementary to the codon on the mRNA.

2. **Codons and Anticodons**: The genetic code consists of codons, which are sequences of three nucleotides on mRNA that specify which amino acid will be added next during protein synthesis. Each codon corresponds to a specific amino acid and matches with a specific tRNA molecule that carries that amino acid.

3. **Types of tRNA**: The number of different types of tRNA is determined by the number of unique codons that exist for amino acids. Since there are 64 possible codons (4 nucleotides, each appearing in triplets), but only 20 standard amino acids, some amino acids are encoded by more than one codon.

4. **Recent Concept**: According to recent concepts, the number of types of tRNA is equal to the number of unique codons that code for amino acids. This means that for every unique codon, there is a corresponding type of tRNA.

5. **Conclusion**: Therefore, the number of types of tRNA is equal to the number of sense codons, which is typically 61 (since three codons are stop codons and do not correspond to any tRNA).

### Final Answer:
According to recent concepts, the number of types of tRNA is equal to 61.

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