Predicting Genetic Outcomes

Use the whiteboard to answer: Write “Hetero” if the alleles show a heterozygous genotype Write “Homo” if the alleles show a homozygous genotype TT

Use the whiteboard to answer: Write “Hetero” if the alleles show a heterozygous genotype Write “Homo” if the alleles show a homozygous genotype Bb

Use the whiteboard to answer: Write “Hetero” if the alleles show a heterozygous genotype Write “Homo” if the alleles show a homozygous genotype gg

Use the whiteboard to answer: Write “Hetero” if the alleles show a heterozygous genotype Write “Homo” if the alleles show a homozygous genotype DD

Use the whiteboard to answer: Write “Hetero” if the alleles show a heterozygous genotype Write “Homo” if the alleles show a homozygous genotype Ff

Write the phenotype for the given alleles Yellow body color is dominant to blue BB

Write the phenotype for the given alleles Yellow body color is dominant to blue Bb

Write the phenotype for the given alleles Yellow body color is dominant to blue bb

Write the phenotype for the given alleles Square shape is dominant to round rr

Write the phenotype for the given alleles Square shape is dominant to round Rr

Write the phenotype for the given alleles Square shape is dominant to round RR

Punnett Squares T T t t Parent Cross: TT x tt Draw a box with a window pane Determine parent genotypes The alleles separate randomly in meiosis One goes on top, and the other on the side T T t t

Punnett Squares T T t T T t T T Parent Cross: TT x tt Used to predict the percent or ratio of POSSIBLE GENETIC OUTCOMES Fill in the alleles, just like a chart. Always have the dominant in front of a recessive T T t T T t T T

Punnett Squares T T t T t T t t T t T t Parent Cross: TT x tt Used to predict the percent or ratio of POSSIBLE GENETIC OUTCOMES Fill in the alleles, just like a chart. Always have the dominant in front of a recessive T T t T t T t t T t T t

Let’s Try it! Draw a punnett square to show the following cross: Spongebob SquarePants recently met SpongeSusie Roundpants at a dance. He is homozygous for his dominant square shape, and SpongeSusie is homozygous recessive round. Predict what their children may look like. Remember – find the parent cross first!

Solution R R r Rr Rr r Rr Rr R=Square r= round Parent Cross: RR x rr What are the chances of having a child that is square? What are the chances of having a child that is round? What are the chances of having a homozygous dominant genotype? 100% R R r Rr Rr 0% r Rr Rr 0%

Let’s Try it! Draw a punnett square to show the following cross: Patrick met Patti at the dance. Both of them are heterozygous for their pink body color, which is dominant to yellow body color. What are their possible children? Remember – find the parent cross first!

Solution B b B BB Bb b Bb bb B=Pink 25% BB b= yellow What are the chances of having a homozygous dominant genotype? Heterozygous? Homozygous recessive? What are the chances of having a child that is pink? What are the chances of having a child that is yellow? B=Pink b= yellow Parent Cross: Bb x Bb 25% BB 50% Bb B b 25% bb B BB Bb 75% b Bb bb 25%

Let’s Try it! Draw a punnett square to show the following cross: Everyone in Squidard’s family has light blue skin, which is dominant for body color. His family brags that they are a “purebred” line. He recently married a nice girl with light green skin, which is the recessive trait. What skin colors might their children have? Use B and b to represent the alleles. Remember – find the parent cross first!

Solution B B b Bb Bb b Bb Bb B=Blue 0% BB b= green What are the chances of having a homozygous dominant genotype? Heterozygous? Homozygous recessive? What are the chances of having a child that is blue? What are the chances of having a child that is green? B=Blue b= green Parent Cross: BB x bb 0% BB 100% Bb B B 0% bb b Bb Bb 100% b Bb Bb 0%

Let’s Try it! Draw a punnett square to show the following cross: One of Squidward’s sons, who is heterozygous for blue body color, married a girl that is also heterozygous. What might their children look like? Remember – find the parent cross first!

Solution B b B BB Bb b Bb bb B=Blue 25% BB b= green What are the chances of having a homozygous dominant genotype? Heterozygous? Homozygous recessive? What are the chances of having a child that is blue? What are the chances of having a child that is green? B=Blue b= green Parent Cross: Bb x Bb 25% BB 50% Bb B b 25% bb B BB Bb 75% b Bb bb 25%

Let’s Try it! Mr. Krabs and his wife recently had a Lil’ Krabby, but it has not been a happy occasion for them. Mrs. Krabbs has been upset since she first saw her new baby who has short eyeballs. She claims the hospital goofed and mixed up her baby with someone else’s baby. Mr. Krabs is homozygous for his tall eyeballs, while his wife is heterozygous for her tall eyeballs. Some members of her family have short eyes, which is recessive. Did the hospital make a mistake? Use a punnett square to solve. Use E to represent the allele.

Solution E E E EE EE e Ee Ee E=Tall eyeballs 50% EE e= short eyeballs What are the chances of having a homozygous dominant genotype? Heterozygous? Homozygous recessive? Did the hospital make a mistake? E=Tall eyeballs e= short eyeballs Parent Cross: EE x Ee 50% EE 50% Ee E E 0% ee E EE EE Yes! There is a 0% chance for short eyes e Ee Ee