Chargaff's Rule. If there is 20% Adenine in the cell, what is the percentage of Thymine, Guanine, and Cytosine found in the same cell?

A = 20%

G=

T=

C=

A = 20%

G = 30%

T = 20%

C = 30%

Explanation:

Recall that the sum of all nitrogenous bases in the DNA nucleotide is equal to 100%. And specific base pairings of Adenine to Thymine (A=T), and Cytosine to Guanine (C=G) must be equal.

So, the percentage of Adenine equal thymine, and that of cytosine equals guanine.

Now, A + T + C + G = 100%

So, if Adenine makes up 20% of the DNA nucleotides, Thymine is also 20%.

Then, 20% + 20% + C + G = 100%

40% + C + G = 100%

C + G = 100% - 40% = 60%

So, divide 60% by 2 to obtain the individual percentage of cytosine and guanine. Each will take 30%

Finally, A = 20%; G = 30%; T = 20%; C = 30%

20% 20% and 40%