Class 12 Biology - Chapter Molecular Basis of Inheritance NCERT Solutions | If a double stranded DNA has 20 per cent
If a double stranded DNA has 20 per cent of cytosine, calculate the per cent of adenine in the DNA.
According to Chargaff’s rule, the DNA molecule should have an equal ratio of pyrimidine (cytosine and thymine) and purine (adenine and guanine). It means that the number of adenine molecules is equal to thymine molecules and the number of guanine molecules is equal to cytosine molecules.
% A = % T and % G = % C
If dsDNA has 20% of cytosine, then according to the law, it would have 20% of guanine.
Thus, percentage of G + C content = 40%
The remaining 60% represents both A + T molecule. Since adenine and guanine are always present in equal numbers, the percentage of adenine molecule is 30%.
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2 Comment(s) on this Question
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Why adenine became 30 if it is equal to G thn it would have become 20%
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