(a) Why is DNA molecule a more stable genetic meterial then RNA ? Explain.
(b) " Unambiguous"," degenerate" and "universal" are some of the salient featuresn of genetic code. Explain.

Explanation

(a) The genetic material should be stable enough not to change with different stages of life cycle.
The DNA strands being complementary if separated by heating come together, when appropriate conditions are provided. But RNA is labile and easily degradable, and also known as catalytic. DNA chemically is less reactive and structurally more stable when compared to RNA . Therefore, among the two nucleic acids, the DNA is a better genetic material.
(b) (i) Unambiguous : A codon codes for only one amino acid, so it is unambiguous and specific.
(ii) Degenerate : Some amino acids are coded by more then one codon, so the code is degenerate.
(iii) Universal : The code is nearly universal. For example, from bacteria to humen UUU would code for phenylalanine (phe) some exceptions to this rule have been found in mitochondria codons and in some protozoans.