Question

Compare and contrast the experimental approaches used by Avery and colleagues, and by Hershey and Chase, to demonstrate that DNA is the genetic material.

a) Both used radioactive isotopes.
b) Avery used bacteria, Hershey used viruses.
c) Avery used viruses, Hershey used bacteria.
d) Both used the same experimental methods.

Answer 1

Avery's experiments involved transforming bacteria with DNA, while Hershey and Chase's experiments involved labeling bacteriophage DNA and proteins with radioactive isotopes to demonstrate that DNA is the genetic material.

Step-by-step explanation:

The experiments conducted by Avery and his colleagues differed significantly from those conducted by Hershey and Chase. Avery's group sought to identify the transforming principle that allowed harmless bacteria to become virulent; through a process of elimination, they discovered that only DNA, not other molecule combinations, was able to transform the bacteria. On the other hand, Hershey and Chase focused on using bacteriophages to determine whether DNA or proteins functioned as the genetic material. They used radioactive isotopes to label the DNA (32P) and proteins (35S) of the viruses, showing conclusively that DNA, the molecule labeled with 32P, was injected into the bacterial cells, proving it to be the genetic material.