Question

What is a triplet codon?
A. Fixed
B. Degenerate
C. Ambiguous
D. Non-wobbly

Answer 1

Hint: The genetic code is made of triplet codons. The genetic code is the genome of an organism. It is a way to express the genome in a form of a string comprising nucleotide bases. Also, the genetic code and the codons share the same features and characteristics.

Complete answer: A codon is a nucleotide triplet. It comprises a set of three nucleotides and thus, it is called a triplet codon. There are mainly four nucleotides that are A, T, G and C. These are nitrogenous bases with a phosphate group and sugar molecule attached to it. The genetic code is thus, a triplet code. Of the 64 codons, 61 are sense codons, those that code for specific amino acids and the remaining three are nonsense codons or termination codons or stop codons. These codons are the signal for the translation process to be terminated. A codon codes for an amino acid when translated and transcripted. There are 20 proteinogenic amino acids coded by these codons. A triplet codon is degenerate, which implies that a single amino acid can be coded by multiple codons. For example, lysine, an amino acid, is encoded by codons AAA and AAG. With the exception of methionine and tryptophan, more than one triplet code can code for an amino acid. The triplet codon cannot be considered fixed. It is because there exist 64 codons and their variation accounts for differences in organisms. A codon that codes for more than one amino acid is an undefined or ambiguous codon. The same code should not code for more than one amino acid, as it could lead to anomalies in normal functioning in the development of unwanted proteins. Therefore, a triplet codon is non-ambiguous. In RNA molecules, a wobble base pair is a pairing of two nucleotides that do not obey the rules of the Watson-Crick base pair. guanine-uracil, hypoxanthine-uracil, hypoxanthine-adenine, and hypoxanthine-cytosine are the four principal wobble base pairs.
Hence, the correct answer is option B.

Note: There are other characteristics of the genetic code. They are as follows:
a. The genetic code is commaless.
b. The genetic code is non-overlapping, which means that codons do not overlap with each other.
c. The genetic code is universally acceptable and understood. It is uniform worldwide.