Explain the properties of genetic material.

Explanation

(i) DNA acts as a genetic material. However, in some viruses like Tobacco mosaic virus (TMV), bacteriophage `theta`B, RNA acts as the genetic material. A molecule that can act as a genetic material should have the following properties:
(ii) Self Replication: It should be able to replicate. According to the rule of base pairing and complementarity, both nucleic acids (DNA and RNA) have the ability to direct duplications. Proteins fail to fulfill this criteria.
(iii) It should be stable structurally and chemically. The genetic material should be stable enough not to change with different stages of life cycle, age or with change in physiology of the organism.
(iv) Griffith.s transforming principle, Heat which killed the bacteria did not destroy some of the properties of genetic material. In DNA the two strands being complementary, if separated (denatured) by heating can come together (renaturation) when appropriate condition is provided.
(v) Further 2. OH group present at every nucleotide in RNA is a reactive group that makes RNA liable and easily degradable. RNA is also known to be catalytic and reactive.
(vi) Hence DNA is chemically more stable and chemically less reactive when compared to RNA.
(vii) Presence of thymine instead of uracil in DNA confers additional stability to DNA.
(viii) It should be able to express itself in the form of .Mendelian characters.. RNA can directly code for protein synthesis DNA, however depends on RNA for synthesis of proteins.
(ix) Both DNA and RNA can act as a genetic material, but DNA being more stable stores the genetic information and RNA transfers the genetic information
(x) Variation through mutation: It should be able to mutate. Both DNA and RNA ara able to mutate. RNA being unstable, mutates at a faster rate.