Class 12th Biology 2016 Set2 Delhi Board Paper Solution
List the criteria a molecule that can act as genetic material must fulfill. Which one of the criteria are best fulfilled by DNA or by RNA thus making one of them a better genetic material than the other ? Explain.
A molecule that can act as genetic material must fulfill the following criteria:
1) It should be able to replicate
2) It should be chemically and structurally stable.
3) It should provide scope for mutation that is required for evolution.
4) It should be able to express itself in form of genes.
DNA is more suitable than RNA and better suited for storage of genetic information while RNA is more suitable for the transmission of genetic information because:
1) Both RNA and DNA can replicate.
2) Presence of thiamine instead of uracil makes DNA more stable
3) Presence of 2’ - OH group in RNA makes it more labile RNA is also catalytic and more reactive, DNA is chemically and structurally more stable.
4) RNA mutates faster than DNA since it is unstable
5) RNA can directly code for protein synthesis while DNA is dependant on RNA for protein synthesis. This shows that protein synthesis has evolved around RNA.
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