Explain any four characteristicsof genetic code.

Explanation

Characteristics of genetic code:
1. Commaless: Genetic code is commaless. This means that the arrangement of triplet codons on m-RNA ia one after the other without a gap or space.
2. Nonambiguous nature: Genetic code is nonambiguous. Each codon specifies a particular amino acid. The only exception is AUG which codes for methionine and GUG which codes for valine. But in the absence of AUG codon, GUG can also code methionine.
3. Degenerate nature: The genetic code is degenerate. There are 61 codons for 20 amino acids. But some amino acids are coded by more than one codon. Hence it is said to be degenerate. E.g.GGG, GGA,GGC and GGu al code for glycine.
4. Polarity: Genetic code could be read only in `5'to3'` direction of m-RNA. This polarity is the important aspect of the genetic code. If also has start and stop signals. Start or initiation codon is AUG while UAG, UAA,UGA are the stop or termination codons.
5. Universality: The genetic code is universal for all the organisms from simple bacteria to complexc organisms. (Exception is seen in mitochondria of yeast and mycoplasma).