1. Heredity

3. What is heredity? Heredity is the passing of traits from parent to offspring. You inherit traits from your parents

4. What are traits? Eye Color Hair Color Height Weight Body Structure Facial Features Skin Color

5. What traits did you inherit from your parents? Complete the genetic scavenger hunt with the people at your table. List any unusual traits that your group members have on the back of the paper. You have 5 minutes to complete this assignment. Be ready to share with the class.

6. How are traits passed? When organisms reproduce, traits are passed from parent to offspring. These traits are carried in DNA, the genetic material found in a cell’s nucleus. DNA acts like a blueprint.

7. Review DNA is located on chromosomes. – You have 23 pairs of chromosomes…pairs 1-22 are autosomes and the 23 rd pair are sex chromosomes. – Homologous chromosomes carry the same gene Genes are pieces of DNA that carry a specific set of instructions – Genes influence the development of traits Half of your genes come from your mom and half come from your dad.

9. Dominant and Recessive Each parent has two genes (or letters) for a trait. These letters are called alleles. Capital letters are called Dominant alleles. When these alleles are present, they take over or show. They are the “stronger” alleles Lower case letters are recessive alleles and are the “weaker” of the alleles. http://naturalsciences.sdsu.edu/classes/lab2.4/trait.jpg

10. Punnett Squares Using Punnett Squares allow us to show what the offspring could look like Allows us to calculate probability of certain genotypes and phenotypes to occur

11. Dominant/Recessive Capital letters are called Dominant alleles. – When these alleles are present, they take over or show. They are the “stronger” alleles Lower case letter are recessive alleles and are the “weaker” of the alleles.

12. Dominant B – brown eyes T – tall C – curly hair W – widows peak F – freckles D – dark skin Recessive b – blue eyes t – short s – straight hair w – no widows peak f – no freckles d – light skin

13. Genome All of an organism’s genetic material. – Everyone has a unique genome that determines their traits…except for identical twins.

14. Genotype and Phenotype Genotype – the inherited alleles, genes.(letters) Phenotype – what the alleles look like when inherited (physical characteristics)

15. Genotype/Phenotype Genotype ff cc Cc tt TT bb Bb Phenotype No Freckles Straight Hair Curly Hair Short Tall Blue Eyes Brown Eyes

16. Homozygous and Heterozygous If the genes are the same, they are homozygous – “homo” means same If the genes are different, they are heterozygous – “hetero” means different Look at SIZE of letter!!

17. Homozygous/Heterozygous?? RR Rr rr Tt tt BB Bb

18. Dominant/Recessive & Homozygous/Heterozygous Dominant – Heterozygous Bb-Brown eyes – Homozygous dominant BB-Brown eyes Recessive – Homozygous recessive bb-blue eyes