Question

If DNA of a particular species was analyzed and it was found that it contains 27 percent A, what would be the percentage of C? a. 27 percent b. 30 percent c. 23 percent d. 54 percent

Short answer

Option c is correct.

Step-by-step solution

Step 1. Introduction

There are two types of nitrogenous bases in a nucleic acid that is pyrimidines and purines. Adenine is complementary to thymine and Guanine is complementary to cytosine.

Step 2. Explanation of the correct option.

Adenosine (A) is complimentary with Thymine (T), which means that there is 27% of A + 27 % of T = 54%

To get the percentage of Cytosine (C) we need to understand that Cytosine and Guanine (G) are also complementary pairs of each other. That indicates that the remaining 46% is half C and half G.

Therefore the percentage of Cytosine will be 23%.

Step 3. Explanation of the incorrect options

Option a is incorrect because the percentage of Cytosine will be 23%.

Option b is incorrect because the percentage of Cytosine will be 23%.

Option d is incorrect because the percentage of Cytosine will be 23%.