Slide 1

Punnett Squares Slide 2 __________ allele: always shows up when the allele is present, represented by a capital letter (R) __________ allele: is hidden when the dominant allele is present, represented by a lowercase letter (r) Dominant Recessive Slide 3 ___________: an organisms physical appearance (round/wrinkled seeds) __________: an organisms genetic makeup (RR, Rr, or rr) Phenotype Genotype Slide 4 _____________: a genotype with 2 of the same alleles (RR or rr) ______________: a genotype with 2 different alleles (Rr) Homozygous Heterozygous Slide 5 A chart that shows all the possible allele combinations (genotypes) the offspring of two parents can have. Slide 6 1. Draw a box and divide it into 4 squares. Slide 7 2. Write the male parents alleles along the top of the square and the female parents alleles along the left side. Example: Father-Rr Mother-Rr R=round seeds r=wrinkled seeds Slide 8 3. Copy the female parents alleles into the boxes to their right. Example: Father-Rr Mother-Rr Slide 9 4. Copy the male parents alleles into the boxes beneath them. Example: Father-Rr Mother-Rr Slide 10 5. The completed Punnett square shows all the possible genotypes of the offspring. Example: Father-Rr Mother-Rr Slide 11 A Punnett square can be used to calculate the probability that a certain combination of alleles will result. Probability offspring will be RR: ___out of ___ or ____% 14 25 Slide 12 A Punnett square can be used to calculate the probability that a certain combination of alleles will result. Probability offspring will be Rr: ___out of ___ or ____% 24 50 Slide 13 A Punnett square can be used to calculate the probability that a certain combination of alleles will result. Probability offspring will be rr: ___out of ___ or ____% 1 4 25 Slide 14 You can also calculate the probability of the phenotypes. R=round seeds r=wrinkled seeds RR and Rr produce _______ seeds: : ___out of ___ or ____% round 3 4 75 Slide 15 You can also calculate the probability of the phenotypes. R=round seeds r=wrinkled seeds rr produces _________ seeds: : ___out of ___ or ____% wrinkled1 4 25 Slide 16 Fur color of mice: Dominant allele: Recessive allele: F (black fur) f (white fur) Slide 17 1.Purebred black mouse (FF) x purebred white mouse (ff) Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% Slide 18 1.Purebred black mouse (FF) x purebred white mouse (ff) FfFfFfFf FfFfFfFf F F f Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% 0 0 00 4 100 (FF, Ff) 4 100 00 (ff) Slide 19 2.White mouse (ff) x white mouse (ff) Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% Slide 20 2.White mouse (ff) x white mouse (ff) ffff f f f Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% 0 0 100 4 0 0 (FF, Ff) 0 0 100 4 (ff) Slide 21 3.White mouse (ff) x heterozygous mouse (Ff) Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% Slide 22 3.White mouse (ff) x heterozygous mouse (Ff) FfFfFfFfff f f F f Probability of: FF: ___ out of 4 or ___% Ff: ___ out of 4 or ___% ff: ___ out of 4 or ___% Probability of: Black mouse: ___ out of 4 or ___% White mouse: ___ out of 4 or ___% 0 0 50 2 2 (FF, Ff) 2 50 2 (ff)