Cataracts Facts. 1  Cataracts are changes in clarity of the natural lens inside the eye that gradually degrade visual quality. The natural lens sits behind the colored part of the eye (iris) in the area of the pupil, and cannot be directly seen with the naked eye unless it becomes extremely cloudy.
Hershey and Chase. Alfred Hershey and Martha Chase did an Experiment in 1952 that was called the Hershey-Chase Experiment. This experiment set out to determine what composed the genetic material of a bacteriophage. A bacteriophage is a virus that infects a bacterium.
In order to prove that proteins are the carriers of genetic information, Hershey and Chase needed to demonstrate that at least a portion of the phageâs protein mass was transferred to the interior of the bacterium. In their first experiment, Hershey and Chase tagged the T2 phage DNA with Phosphorous-32, a radioactive form of the element. Because phosphorous can be found in large quantities in DNA, but in only trace amounts in protein, the researchers could track the location of DNA and protein according to the radiation concentrations.