1. Human Inheritance

2. What makes a super model The model system for genetic studies: What makes a good model system –The fruit fly –The meal worm –The nematode Why humans are not good model systems

3. The human cell Review diploid number (46) Review mitosis especially metaphase What’s a Karyotype? Review haploid number and sex determination

4. Genes and people Human generation is about 20 years so genetics relies on family and medical history The pedigree analysis Many human traits are inherited by the action of genes that have dominant and recessive allele.

5. Classic Inheritance Dominant and recessive Rh blood group is a Dom/rec condition Rh pos is dominant, Rh neg is recessive Other examples on the class web site

6. Multiple alleles and co-dominant alleles Multiple alleles: A type of gene determined by more than two alleles ABO blood type example; blood type is determines by three alleles A and B are co-dominant; both alleles can be expressed

7. Polygenic traits Traits that are determined by more than one gene Height, skin color, eye color Environmental conditions can affect the phenotype of polygenic traits

8. Incomplete Dominance The heterozygous phenotype shows a trait somewhere in between the two homozygotes. In flowers, heterozygote is pink when one homozygote is red and the other is white In humans, hair curliness is incomplete. The homozygotes are straight hair and curly chair; the heterozygote is wavy hair.