Question

Genetic code is degenerate because
A. Codons have same energy level
B. Each codon has a different meaning
C. Each codon has many meanings
D. Many codons have same meaning

Answer 1

Hint: Sequence of three nucleotides together forming a genetic code in DNA or RNA molecule is called a codon. Genetic code is the set of rules using which living cells translate the information from DNA or RNA.

Complete answer:
Let’s see the properties of the genetic code-
A set of three nucleotides codes for an amino acid in a protein, i.e. genetic code is a triplet
The genetic code is degenerate. This means that different codons can code for the same amino acid. e.g. UCU and UCC both code for serine.
It is unambiguous and universal as a specific codon will only code for a particular amino acid and will be valid for all the organisms; this means that a specific codon will code for the same amino acid in all the organisms.
There is no use of punctuation, i.e. each nucleotide is adjacent to the other.
It is a non overlapping code. It means that the code is read sequentially and a nucleotide is part of only one triplet.
The codons have a fixed polarity and are always read from 5’ → 3’.
As discussed above, the genetic code is degenerate as a specific amino acid can be coded by many codons, i.e. many codons have the same meaning.

Hence, the correct answer is option D.

Note:
START AND STOP CODONS:
1. AUG is the start codon and also codes for methionine
2. UAG, UAA, and UGA are the stop codons and do not code for any protein as they cannot be read by tRNA.