AP BIOLOGY

Detailed explanation-1: -Their experiments led to an unequivocal proof to DNA as genetic material. Bacteriophages (viruses that affect bacteria) were the key element for Hershey and Chase experiment. The virus doesn’t have their own mechanism of reproduction but they depend on a host for the same.

Detailed explanation-2: -The most well-known Hershey-Chase experiment was the final experiment, also called the Waring Blender experiment, through which Hershey and Chase showed that phages only injected their DNA into host bacteria, and that the DNA served as the replicating genetic element of phages.

Detailed explanation-3: -In their experiments, Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the hereditary material.

Detailed explanation-4: -Alfred Hershey and Martha Chase showed that only the DNA of a virus needs to enter a bacterium to infect it. Their experiment provided strong support for the idea that genes are made of DNA. They firmly restated the conclusion that Avery, et al. had more tentatively proposed in 1944.

Detailed explanation-5: -Answer: The 32P (phosphorus) was used in the Hershey-Chase experiment because phosphorus is present in deoxyribonucleic acid (DNA), but not in protein. Contrastingly, sulfur (S) is present in the amino acids cysteine and methionine. Hence, 35S was used to label only the proteins because DNA does not contain sulfur.