Genetics Genetics Genetics is the study of how

Genetics

Genetics �Genetics is the study of how traits are inherited in offspring.

Genetics �Gene: Segment of chromosome (DNA) that codes for a trait

Genetics �Allele: Different form of the same gene. �Example: Skin Color (Color, Albino)

Genetics �Humans normally have two alleles for each gene.

Genetics �Dominant: Trait that gets expressed from dominant allele.

Genetics �Phenotype: Observable physical or behavioral trait

Genetics �Genotype: Genes (Alleles) that code for a trait

Genes and Traits part 2 �Homozygous: having the same forms (alleles) for a gene on both chromosomes. �Also said to be purebred.

Genetics �Homozygous Dominant = AA �Homozygous Recessive = aa

Genetics �Heterozygous: having different forms (alleles) for a gene on both chromosomes. �Also said to be hybrid.

Heterozygous = Aa, or a. A Genetics �Monohybrid Crosses �Gene: Albinism �Dominant Allele: A = normal skin color �Recessive Allele: a = albino

Heterozygous = Aa, or a. A Genetics �Cross a heterozygous individual with a heterozygous individual: Aa X Aa A AA Aa aa

Heterozygous = Aa, or a. A Genetics �Cross a homozygous dominant individual with a homozygous recessive individual: AA X aa a a A Aa Aa

Heterozygous = Aa, or a. A Genetics �Test Cross: Cross a homozygous recessive individual with an unknown (homozygous dominant or heterozygous): aa X A? a a A Aa Aa ? A? A?

Heterozygous = Aa, or a. A Genetics �The outcome determines the offspring. If half of the offspring are albino, then the unknown is heterozygous (Aa). a a A Aa Aa a aa aa

Heterozygous = Aa, or a. A Genetics �If all of the offspring have normal skin color, then the unknown is homozygous dominant. a a A Aa Aa