Question

Assertion : $tRNA$ recognises its corresponding codon in $mRNA$.
Reason : For each codon, there is an individual $tRNA$.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

$tRNA$ has an anticodon loop which has $7$ bases, out of which three bases form anticodon for recognising and attaching to the codon of $mRNA$. Since there are $61$ codons specifying amino acids, the cell should contain $61$ different $tRNA$ molecules, each with a different anticodon. Actually, however, the number of $tRNA$ molecule types discovered is much less than $61$. This implies that the anticodons of some $tRNAs$ read more than one codon on $mRNA$.