Punnett Square Practice

Geneticist Reginald Punnett developed a diagram that can be used to predict the way genes will combine when passed from parents to offspring.  Each trait is represented by two letters.  Two capital letters, such as RR, indicate a pure dominant trait.  The dominant trait will occur in an organism with this genotype.  Two small letters, such as rr, indicate a pure recessive trait.  The recessive trait will occur in an organism with this genotype.  A capital letter and a small letter, such as Rr, indicate a hybrid trait.  The dominant trait will occur in this organism, but the individual will be a carrier of the recessive trait.

Punnett squares only predict probability.