Chapter 2 Summary

The topics covered in this chapter can be summarized as follows:

• The alleles of loci in different chromosomes are inherited independently of each other.
• The expected phenotypic ratio of a dihybrid cross is 9:3:3:1.
• The 9:3:3:1 ratio can be modified if the loci are not simple dominant/recessive to each other,  if there are gene interactions, or if the two loci are linked.
• A test cross gives a ratio of 1:1:1:1 for loci that assort independently.

Take a look at this video, Mendelian Genetics and Punnett Squares, from Professor Dave Explains (2017), which gives a great summary of what we have covered so far!

Reference

Professor Dave Explains. (2017). Mendelian genetics and Punnett squares [Video file]. YouTube. https://www.youtube.com/watch?v=3f_eisNPpnc