Why is DNA a better genetic material when compared to RNA ? (3 marks)
(i) RNA is single stranded while DNA is double stranded.
(ii) 2'OH group present at every nucleotide in RNA is a reactive group and makes RNA labile and
easily degradable. RNA is more catalytic so highly reactive. DNA is less reactive, has H group
instead of OH group.
(iii) In DNA thymine is present at the place of uracil. This gives additional stability to DNA.
(iv) Both DNA and RNA are able to mutate. RNA is unstable, so mutates at a faster rate, e.g.,
viruses having RNA genome have shorter lifespan, mutate and evolve faster.
(v) RNA can directly code for the synthesis of proteins, hence can easily express the characters
however DNA is dependent on RNA for synthesis of proteins. The protein synthesising machi-
nery has evolved around RNA. Both DNA and RNA can function as genetic material, but DNA is
more stable than RNA.