In human DNA, adenine (A) makes up approximately 30.9% of the bases, and guanine (G) makes up approximately 19.9% of the bases. Therefore, the percentage of thymine (T) and cytosine (C) are:

A. 19.8% T and 19.8% C.
B. 19.8% T and 29.4% C.
C. 29.4% T and 19.8% C.
D. 29.8% T and 29.8% C.
E. 19.9% T and 30.9% C.

Can you please explain with some details?

In human DNA, there are nitrogenous base pairings- A, T C and G. A pairs with T and C pairs with G. Because they're a pair, the ratio of A:T and C:G should be as close to 1:1 as possible. Since A makes up approx 30.9%, T should be either C or D. As G makes up approx 19.9%, we can rule out option D, therefore the answer is C! Hope this helps (:

Answered by waniibunny | 2024-06-10

In human DNA, adenine (A) is paired with thymine (T) and guanine (G) is paired with cytosine (C). For the given percentages, adenine is approximately 30.9%, which means thymine should also be approximately 30.9%, while guanine at 19.9% means cytosine will also be 19.9%. The closest answer choice based on this reasoning is option E: 19.9% T and 30.9% C.
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Answered by waniibunny | 2024-10-02