Question

If the cystine content of double stranded DNA is 20 percent of the total bases then the adenine content will be

• A. 40 percent
• B. 30 percent
• C. 20 percent
• D. 10 percent

Hint:

In double-stranded DNA the amount of adenine is always equal to thymine and the amount of guanine equals cystine due to base pairing rules

Answer 1

The Correct Option is D

Due to base pairing, if cystine is 20%, guanine will also be 20%. This leaves 60% for adenine and thymine. Although adenine pairs with thymine in equal amounts, the adenine content is 10%.