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.
A quasi-experiment is an empirical study used to estimate the causal impact of an intervention on its target population.uasi-experiments are also effective because they use the pre-post testing. This means that there are tests done before any data is collected to see if there are any person confounds or if any participants have certain tendencies.