Question

Question #6d63d

Answer 1

30%

Explanation:

Nitrogenous Bases
The four nitrogenous bases are adenine, thymine, cytosine, and guanine. Adenine can only form bonds with thymine, and similarily cytosine can only form bonds with guanine, due to the chemical structure of each base (Adenine and guanine and both purines, because they have two carbon rings, while cytosine and thymine are pyrimidines, with only one carbon ring).

Step-by-Step Explanation
We can use the above properties to figure out the percentage of cytosine in 3 steps:

1. Since adenine can only bond with thymine, then the percentage of thymine has to be 20%.

2. Because 20% of the bases are adenine and 20% are thymine, the remaining 60% must be cytosine and guanine.

3. Since there must be one guanine for every cytosine, because they can only bond with each other, the percentage of guanine and cytosine is 30% each.

Here's the breakdown in a chart, so it's easier to visualize. The reasoning for each percentage is in parentheses).