Question

A phenomenon where the third base of t-RNA at its 5' end can pair with a complementary base of m-RNA is called

• A. Degenerency
• B. Wobbling
• C. Universality
• D. Colinearity

Answer 1

The correct option is A Degenerency

The genetic code is degenerate which means that one codon can specify more than one amino acid. For example, GAA and GAG both specify same amino acid which is glutamic acid and not any other amino acid. Degenerate codons differ in their third positions.

There are 64 codons and only 20 amino acids. Due to this the redundant codons which specify the same amino acid are related to each other by a sequence. For example, leucine is specified by codons CUU, CUA, CUC and CUG. All the codons are same except the ones at third position. The third position is known as wobble position which can change but still specify the same amino acid.

Genetic code is universal which means that it is same for all organisms raging from bacteria to man except certain bacteria, mitochondria and protists where minor variations can be seen.

Genetic code is collinear which means that the sequence of amino acids in a polypeptide chain corresponds to the sequence of bases in DNA that codes for it. Any change in codon will change the amino acid in polypeptide.

Thus, the correct answer is option A.