Question

Before the three-dimensional structure of DNA was discovered, scientists knew that DNA contained nitrogenous bases. The table below shows the percentages of the nitrogenous bases in a DNA sample. Which rule can be used to determine the percentages of the missing nitrogenous bases? Complete the table AND explain your answer.

Base Percent:
Adenine 23
Thymine
Cytosine 27
Guanine

Answer 1

Complementary base pairing rules

Thymine 23

Guanine 27

Step-by-step explanation:

Complementary base pairing rules state that adenine always pairs with thymine, and cytosine always pairs with guanine in a double stranded DNA helix This means that in a double stranded DNA molecule, there will be exactly the same amount of thymine as adenine, and exactly the same amount of guanine as cytosine. Therefore, there is 23% of thymine, and 27% of guanine