Punnet Squares

1. Punnet Squares

2. PUNNET SQUARES TALL Plants SHORT Plants DOMINANT RECESSIVE T TT (Homozygous Dominant) OR Tt (Heterozygous) t tt (Homozygous Recessive) ALLELES Homozygous Tall TT Homozygous Short tt

3. Now that you know the parents… T T t Parents: ______ x ______ TT tt t

4. Now that know how to set up the Punnett Square.. Genotype: _____ _____ _____ T T tt Tt TT Parents: ____ x ____ t T t 0 (0%) 4 (100%) 0 (0%) T t TT tt Phenotype: _______ _______ SHORT t T t T t TALL 4 (100%) 0 (0%) TT TALL 0 0 /4 = 0% 4 /4 = 100% TALL 4 Tt 0 SHORT 0 /4 = 0% tt 100% Tall (Tt)

5. Now that we have the numbers worked out… TT (Homo. Dominant) ORTt(Heterozygous) tt(Homo. Recessive) Tall Short The capital ‘T’ allele for the tall trait is COMPLETELY DOMINANT over the lower case ‘t’ for the recessive short trait.One dominant trait is all that is needed for the dominant trait to be expressed.

6. Let’s put it all together… l L Long-haired l L l l l Short-haired L = long-haired l L l l l l = short-haired Ll (Heterozygous) Genotype: _____ _____ _____ LL Ll ll ll (Homo. Recessive) 0 (0%) 2 (50%) 2 (50%) Parent: _____ x _____ ll Ll Phenotype: _______ _______ LONG SHORT 2 (50%) 2 (50%)

7. R r Red flower r R r r r White flower R = Red (RR or Rr) r R r r r r= white (rr) Genotype: _____ _____ _____ Rr Rr (Heterozygous) RR rr 2 (50%) 2 (50%) 0 (0%) rr (Homo. Recessive) Phenotype: _______ _______ WHITE RED 2 (50%) 2 (50%)

8. Your turn…