Chapter 23, Problem 98A

Interpretation Introduction

Interpretation:

The percentage of the other three bases except adenine that are present in the DNA strand needs to be determined.

Concept introduction:

DNA stands for deoxyribonucleic acid and RNA stands for ribonucleic acid. DNA includes four bases such as adenine (A), guanine (G), cytosine (C), and thymine (T). RNA consists of four bases: adenine, cytosine, uracil, and guanine.

Answer to Problem 98A

The DNA molecule has 20% adenine, 20% thymine, 30% cytosine and 30% guanine.

Explanation of Solution

Given that the DNA molecule has 20% adenine. So, it will also have 20% thymine. The remaining 60% of the DNA is cytosine and guanine. As cytosine and guanine combine in equal amounts, so guanine must be present in 30% and cytosine must also be present in 30%.

Conclusion

In the DNA molecule,

A=T = 20%

C=G = 30%