Experiment 3: Characterizing the F2 generation

When members of the F1 generation are crossed to one another, the resulting organisms are known as the F2 generation. 

In your previous study, if you looked at enough F2 individuals, you should have found that there are individuals that express the recessive trait as well as individuals that express the dominant trait.   Our next set of experiments are aimed at answering some questions about the F2 individuals.

To do this, we will use a specific type of cross, known as a "test-cross".  In a test cross, we cross the organism under study with an organism that expresses recessive traits and which breeds true.  A specific type of test cross involves the recessive parental strain - this is known as a "backcross".

Experiment 3: Design an series of experiments to answer the following questions.
  • Is there a reproducible ratio of individuals that express the dominant versus recessive trait in the F2 generation?
  • It this ratio the same or different for different dominant:recessive trait pairs?
  • Do all F2 organisms breed true? 
  • Based on their breeding behavior, how many different types of F2 individuals are there? 
  • Use javaGenetics (not currently working) to carry out your experiments.  In your report describe your experiments, your data and the answers to the questions posed!

Use Wikipedia to look up concepts | edited/revised 25-Jul-2009