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.
Definition of Quasi-Experiment. A quasi-experiment is designed a lot like a true experiment except that in the quasi-experimental design, the participants are not randomly assigned to experimental groups.