Final answer:
Hershey and Chase would have concluded that both DNA and proteins contribute to genetic inheritance if both 32P and 35S were found in the bacteria. However, their experiment demonstrated that only 32P, indicative of DNA, was present in the bacteria, affirming DNA's role as the genetic material.
Step-by-step explanation:
If Hershey and Chase had found both radioactive 32P and 35S in the bacteria in their experiment, they would have concluded that both DNA and proteins were involved in the genetic inheritance of the bacteriophages. However, in their actual experiment, only 32P, the marker for DNA, was found inside the bacteria, leading them to conclude that DNA was the genetic material.
They used radioactive sulfur (35S) to label the protein coat of the phages because sulfur is present in some amino acids which are the building blocks of proteins but not in DNA. Conversely, they used radioactive phosphorus (32P) to label the DNA since phosphorus is a key component of DNA and RNA but is not typically found in proteins.
This experiment was pivotal in showing that DNA, and not protein, was responsible for hereditary information in phages. The presence of 32P in the bacterial pellet after centrifugation confirmed this, as the labeled DNA was found inside the bacteria while the 35S, labeling the protein, was left in the supernatant.