Questions: Question 13 0.25 pts Which of the following characteristics allowed Hershey and Chase to determine whether the genetic material was made of DNA or protein? DNA contains phosphorus, whereas protein does not. DNA contains sulfur, whereas protein does not. DNA contains purines, whereas protein includes pyrimidines. DNA contains nitrogen, whereas protein does not.

The answer is the first one: DNA contains phosphorus, whereas protein does not.

Explanation for each option:

1. DNA contains phosphorus, whereas protein does not.

   • Correct. Hershey and Chase used radioactive isotopes to label DNA and protein in their experiments. They used phosphorus-32 to label DNA because DNA contains phosphorus in its backbone. Proteins, on the other hand, do not contain phosphorus, allowing them to distinguish between DNA and protein.

2. DNA contains sulfur, whereas protein does not.

   • Incorrect. Proteins contain sulfur in the amino acids cysteine and methionine. Hershey and Chase used sulfur-35 to label proteins, not DNA.

3. DNA contains purines, whereas protein includes pyrimidines.

   • Incorrect. Both DNA and RNA contain purines (adenine and guanine) and pyrimidines (cytosine and thymine in DNA, uracil in RNA). Proteins do not contain purines or pyrimidines.

4. DNA contains nitrogen, whereas protein does not.

   • Incorrect. Both DNA and proteins contain nitrogen. DNA has nitrogenous bases (adenine, thymine, cytosine, and guanine), and proteins are made up of amino acids, which also contain nitrogen.

Summary: Hershey and Chase were able to determine that DNA is the genetic material because DNA contains phosphorus, which they could label with a radioactive isotope, whereas proteins do not contain phosphorus.