1. Punnett Squares Why do we all look just a little like our moms and dads?

2. What – How – Why? What: Utilize a Punnett square to predict the patterns of a cross. (2.7d) RWC -3.2f/g, 4d HOW: Given a word problem, complete and analyze a Punnett square to predict and justify the resulting patterns of a cross. Why: What is the chance that you may have had different color eyes?

3. What you have to do at the end of today! One cat carries heterozygous, long-haired traits, and its mate carries homozygous short- haired traits. Long hair is DOMINANT. Use a punnett square to analyze and fill in the chart. PhenotypeGenotype% of offspring

4. What do we need to know in order to answer this question? One cat carries heterozygous, long-haired traits, and its mate carries homozygous short- haired traits. Use a Punnett square to determine the genotype and phenotype probability of their offspring.

5. Steps to get there 1.Pick the following statements out of the question: “One cat carries heterozygous, long-haired traits” “its mate carries homozygous short-haired traits” Allele – different forms of genes (ONE Letter) – Examples: Dominant and recessive Heterozygous: Two DIFFERENT alleles. Homozygous: Two of the SAME alleles.

6. Practice Write down the key statements in the following genetics problem: – Suppose a man who is heterozygous for tongue- curling marries a woman who is also heterozygous for this trait. What are the possible genotypes and phenotypes of their children?

7. Practice Pick out the key statements in the following statement: – Suppose a man who is heterozygous for tongue- curling marries a woman who is also heterozygous for this trait. What are the possible genotypes and phenotypes of their children?

8. 2. Using the information copy and fill in the following chart: PhenotypeAlleleGenotype RedRRR or Rr Whiterrr Looking at the chart, what do you think phenotype means?

9. Vocab!! Phenotype – Physical Characteristic/Trait (Color, tongue curling, etc..) Genotype – Genetic make up (TT, Tt, tt) Homozygous – TT, tt » Dominant – TT » Recessive - tt Heterozygous - Tt

10. Practice - Together Let’s put the two steps together 1 st – pick out the key statements – If one parent is homozygous dominant for free earlobes, while the other is heterozygous for free earlobes. Use a Punnett square to show the genotype and phenotype for their offspring. Homozygous dominant for free earlobes Heterozygous for free ear lobes 2 nd – Fill out the chart PhenotypeAlleleGenotype Free ear lobesFFF or Ff Attached ear lobesfff

11. Complete BOTH steps in your notebooks!! A man that is heterozygous for a widow’s peak marries a woman is homozygous recessive for no widow’s peak. 1. Write down KEY INFORMATION. 2. Fill in the chart. PhenotypeAlleleGenotype

12. Steps to get there 3. Show the genotypes of the parents RR x rr 4. Place on a punnett square RR R Rr r rr Or

13. KFed is heterozygous for brown hair, so…. His genotype is Bb B b And Britney is homozygous for blonde hair, so…. Her genotype is bb bb Bb bb

14. Steps to get there Predict what the top row of letters (other parent’s genotype) should be and write the rule for crossing. B b BB Bb bb

15. Practice In humans, free earlobes are dominant over attached ear lobes. If one parent is homozygous dominant for free ear lobes, while the other has attached earlobes, can they produce any children with attached earlobes? Justify your answer. 1. YES2. NO

16. Dominance (based on PHENOTYPE!!!) Simple = Rr Big letter always dominant – Black hair vs. Blonde Incomplete = RW two dominant so there is blending – End up with a third phenotype Red + White  Pink Co-Dominance = BW – Black cow + white cow  Spotted cow

17. Which is which?

18. Independent Practice Fill in and analyze these punnett squares!!

19. What – How – Why? What: Utilize a Punnett square to predict the patterns of a cross. (2.7d) RWC -3.2f/g, 4d HOW: Given a word problem, complete and analyze a Punnett square to predict and justify the resulting patterns of a cross. Why: What is the chance that you may have had different color eyes?

20. DOL: 6pts!! One cat carries heterozygous, long-haired traits, and its mate carries homozygous short- haired traits. Long hair is DOMINANT. Use a punnett square to analyze and fill in the chart. PhenotypeGenotype% of offspring