1. Extending Mendelian Genetics
How traits are inherited
Sections 7.1, 7.2

2. Terms for this chapter please define these as homework
Carrier
Sex-linked gene
Incomplete dominance
Codominance
Multiple allele
Polygenic traits
Pedigree
karyotype

3. How Sex is determined
the difference in the X and Y chromosome leads to a difference in the inheritance of traits located on the sex chromosomes

4. Sex-linked Genes
Most sex-linked traits are considered to be influenced by the X chromosome
The Y chromosome does carry some but it only affects the males

5. Punnett Squares & sex-linked traits
Genotype
Phenotype
XRXR
Normal
female
XRXr
Carrier
XrXr
Affected
XRY
male
XrY

6. Males statistically have a higher incidence of sex-linked traits because only one chromosome needs to carry the recessive allele

7. Hemophilia is sex-linked

8. Incomplete dominance Heterozygous individual shows a blend of two traits

9. Codominance Heterozygous individual expresses both alleles

10. Polygenic traits
Trait is determined by the combined effect of one or more genes
Human skin, hair, height, and eye color