1. Getting Started: How are human genetics studied? Concepts/Vocabulary: – Co-dominance – Incomplete Dominance – Pedigree – Genetic carrier

2. Getting Started: Incomplete Dominance Inheritance: – In heterozygous offspring there is a blending of both traits. – Example: White flowers are crossed with red flowers and the heterozygous offspring have pink flowers. – Since neither trait is dominant over the other we use different capital letters to represent the alleles. – RR = Red – WW = White – RW = Pink.

3. Getting Started: Co-Dominance Inheritance: – The prefix “co” means “together”. Cooperate = work together Coexist = exist together Cohabitate = live together – Both traits appear together in the heterozygous individual. – Example: A white dog is mated with a black dog. Their offspring that are heterozygous are black and white.

4. Getting Started: Humans have 3 different blood types. – Type A – Type B – Type O

5. Getting Started: Human blood type follows a co-dominant pattern of inheritance. – The A allele and the B allele are both dominant over the O allele.

6. T = Red allele, t = white allele. Inheritance Pattern Homozygous Recessive Homozygous Dominant Heterozygous Dominant Trait Inheritance Incomplete Inheritance Co-dominance

7. T = Red allele, t = white allele. Inheritance Pattern Homozygous Recessive Homozygous Dominant Heterozygous Dominant Trait Inheritance tt = white flowers TT = red flowersTt = red flowers Incomplete Inheritance WW = white flowers RR= red flowersRW = pink flowers Co-dominanceWW = white flowers RR = red flowers RW = red & white flowers.

8. Getting Started: Pedigree: – A family history of traits, used to study human conditions.

9. Getting Started: Genetic carrier: – A heterozygous individual – A genetic carrier can pass on the recessive trait but does not show signs of the recessive trait.

10. Getting Started: Much like graphs and charts, pedigrees have features that must be present to be effective. In your lab groups develop a set of rules for reading or constructing pedigrees.

11. Getting Started: During the Activity: – Use Student Sheet 66.1 (3 pages) as you work through the Stopping To Think Question.