Codominance What does co mean expresses both alleles

Codominance • What does co- mean? • _______ expresses both alleles’ conditions – Ex. • Usually uses both capital letters – Key:

Codominant Punnett Square Key: Genotype and Phenotype Proportions of offspring: __ __ _ _ ___ __ ___

Now let’s cross two heterozygotes. __ __ Results:

Polygenic Inheritance • What does poly- mean? • Trait controlled by ________ – May be on ________ chromosomes • Shows a _______, ______ is most common phenotype • _________ case letters used

_______: A polygenic trait Number of Genes Involved in Skin Color Expected distribution- 4 genes Number of individuals Observed distribution of skin color Expected distribution- 1 gene Light Range of skin color Expected distribution- 3 genes Dark

Skin Color • Due to __ genes • Genotypes darkest to lightest:

Influence of External Environment • Example(s): • Notes:

Influence of Internal Environment • Example(s): • Notes:

Blood type quick facts • _______ are called erythrocytes • Proteins on their surfaces are called _____, controlled by _______ • _____ make ______ to _________ – Examples of foreign substances: • 4 phenotypes: • 3 alleles:

Phenotype A • Notes: • Surface molecule __ is produced. Surface molecule A

Phenotype B • Notes: • Surface molecule ___ is produced. Surface molecule B

Phenotype AB Surface molecule B • The l. A and l. B alleles are ______. • Notes: Surface molecule A

Phenotype O _____ antigens produced

Use your knowledge to fill out this chart Blood Type A B AB O Antigens Antibodies Can receive Can give to from

Possible genotypes for each phenotype: • A= • B= • AB = • O=