Question

You have isolated a newly discovered viral strain and sequenced its genome. The genome contains 30% adenine, 40% guanine, 25% cytosine, and 5% thymine. You conclude that the virus has a single-stranded DNA genome. Based on what evidence can you make this conclusion?

Answer 1

Answer:

It is a single stranded DNA since adenine percentage is not equal to that of thymine and the percentage of guanine is not equal to cytosine.

Explanation:

According to Chargaff rule, the amount of adenine in a double-stranded DNA is always equal to that of thymine. This is due to the fact that adenine pairs with thymine in a double-stranded DNA. Likewise, the amount of guanine is always equal to that of cytosine in a double-stranded DNA.

The percentage of four types of bases in the genome of the virus does not follow the Chargaff rule and hence, it is a single-stranded DNA.