Punnett Square Practice By:

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Instructions Today you will learn about Punnett Squares. If you are not already viewing this in presentation mode, please press the F5 key to start viewing it in presentation mode so you can see how to do the presentation.

Instructions – please read A green pea plant (GG) is being crossed with a green pea plant (Gg) yellow is the recessive color. Parent 2 Parent 1 Parent 1 has a Genotype of GG and a Phenotype of Green. Parent 2 has a Genotype of Gg and a Phenotype of Green. This means G is dominant and will make a green phenotype if there is GG or Gg. That means g is recessive and will make a yellow phenotype if there is gg. We’re now going to predict what their children would be like.

G G G g Instructions – please watch To predict what a parent will produce, we use a Punnett Square, named after the man who invented it. A green pea plant (GG) is being crossed with a green pea plant (Gg) yellow is the recessive color. See how the GG from Parent 1 separates into each space. Step 1 – Put the parents on the outside of the Punnett Square G G G Notice how the Gg from Parent 2 separates into each space. g

Instructions – please watch To predict what a parent will produce, we use a Punnett Square, named after the man who invented it. A green pea plant (GG) is being crossed with a green pea plant (Gg) yellow is the recessive color. Step 1 – Put the parents on the outside of the Punnett Square Step 2 – Take one allele from each parent and combine them in each box. G G G G G G G Your Punnett Square is complete! g G g G G

Instructions – Please Watch A green pea plant (GG) is being crossed with a green pea plant (Gg) yellow is the recessive color. Only one box is Gg, which is still dominant, but it is heterozygous dominant. 1 out of 4 boxes means it is 25%. Step 3 – Figure out the probability of each Genotype and Phenotype. This would be GG 3 out of the 4 boxes are GG, so that equals 75% The Phenotype is Green because it is GG G G Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous 75% Green Dominant Heterozygous 25% Recessive homozygous 0% Yellow G G G G G g G g G G

Now You Try! Be careful with capitalization! You will fill in the Punnett Square on each slide. You will also figure out what percent of the boxes are: Dominant Homozygous (2 capital letters: GG) Dominant Heterozygous (1 capital, 1 lowercase: Gg) Recessive Homozygous (2 lowercase letters: gg) Remember… 4 out of 4 = 100% 3 out of 4 = 75% 2out of 4 = 50% 1 out of 4 = 25% Be careful with capitalization!

A green pea plant (Gg) is crossed with a yellow pea plant (gg). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A tall plant (TT) is crossed with a tall plant (Tt). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A tall plant (Tt) is crossed with a short plant (tt). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A red flower (Rr) is crossed with a white flower (rr). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A white flower (rr) is crossed with a white flower (rr). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A black chicken (BB) is crossed with a black chicken (BB). Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

Now for Something New Now we will take this one step further. You will have to figure out what the parents’ alleles are based on the description. Remember… Homozygous means two of the same Heterozygous means two different You can have dominant homozygous (2 capital letters: BB) You can have recessive homozygous (2 lowercase letters: bb) You can have dominant heterozygous (1 capital letter, 1 lowercase letter: Bb)

A homozygous dominant brown mouse is crossed with a heterozygous brown mouse (tan is the recessive color). Genotype Phenotype Parent 1 Parent 2 Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

Two heterozygous white (brown fur is recessive) rabbits are crossed. Genotype Phenotype Parent 1 Parent 2 Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

Two heterozygous red flowers (white flowers are recessive) are crossed. Genotype Phenotype Parent 1 Parent 2 Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous

A heterozygous white rabbit is crossed with a homozygous black rabbit. Genotype Phenotype Parent 1 Parent 2 Calculate the percent outcome for Genotype and describe the phenotype for each combination. Genetic Combination Genotype Phenotype Dominant Homozygous Dominant Heterozygous Recessive homozygous