1. Heredity & Punnett Squares

2. If you look around the room you share some physical characteristic with your classmates. What do you see that you have in common?

3. Phenotype Probability Recessive Trait Dominant Trait Genes Punnett Square Genotype Heredity

4. Is the passing on of traits (characteristics) from parents to offspring. What traits were passed on to these kittens?

5. Gregor Mendel Born 1822 in Austria Was a monk Studied and bred pea plants He wondered why some traits are passed to other offspring and some are not.

6. Genes Are the set of DNA instructions that carry hereditary information. Passed from parents Located on DNA which makes up chromosomes.

7. Dominate Traits The trait that will always appear. bbBbBb bBbB

8. Recessive Traits The trait will that recede or not be shown is recessive. bb

9. Punnett Square Used to see all the possible combinations of genes from a parent. Bb bb B b bb Eye Calculator

10. Alleles Are half of the genotype. Ex. Bb

11. Probability Is the mathematical chance or % chance of inheriting a gene. In a Punnett Square…. If one square contains the gene for brown hair, there is 25% chance of that child having brown hair. If it’s two squares, it’s 50%. If it’s three squares, it’s 75%. If it’s four squares, it’s 100%.

12. Homozygous When the gene is purebred. EX. A rabbit with black fur and the gene FF.

13. Heterozygous The gene is a hybrid. EX. A rabbit with black fur and the gene Ff.

14. Incomplete Dominance You may hear it called co-dominance, although that’s a little bit different. Is the blending of intermediate traits Ex. Skin color.

15. Incomplete Dominance Neither allele is dominant or recessive Organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parents From teacherweb.com

16. Incomplete Dominance Ex: Cross a red flower (RR) with a white flower (WW) and the offspring will be pink (RW)! From teacherweb.com

17. So, how does information move from gene to physical trait? Genotype Is the inherited combination of genes from the Punnett square. Ex. Bb Phenotype An organism’s inherited trait. Ex. Brown

18. Practice a Punnett using the blood types A and AB.

19. Take a moment to create and then explain a Punnett square to your partner.