Sunday 22 September 2013

Branch Diagrams to Solve Phenotype and Genotype Questions

A lot of students approached me about question 2.27 from the Sanders and Bowman textbook.  I can't use their question directly, but I came up with a similar one.   I like this question because it can be used to practice how branch diagrams are used, and for both phenotype and genotype.

Try this out on your own.  I have two videos for the answers.   One is for a-c which are phenotype-related and were easier for most students.  The second video is for d&e which involve genotypes.  Note that you can solve these without using branch diagrams!  The student Study Guide and Solutions Manual shows other ways to correctly determine the answers.

Part 1:  Phenotypic ratios.

Part 2:  Genotypic ratios
See?  Branches aren't so hard!