Pea In Your Genes

Gregor Mendel Liked to play with pea Noticed that certain Characteristics (inheritable physical features) showed up or disappeared in peas. plants.

Characteristics Inheritable physical features – such as yellow peas or wrinkled peas. Come from Genes – Which come from your parents. Also called Traits – could be pea color or pea shape.

A single trait can be expressed (shown) in different ways. Allele is the different representation of the same trait. Ex. Seed color: Yellow or Green Yellow is one Allele for Seed Color Green is another Allele

Genotype & Phenotype Genotype – “code” for a trait Phenotype – what you actually see. Yellow peas – Use Y to represent Yellow Green peas – Use y to represent Green

Yellow and Green Peas GenotypePhenotype YY – Yellow Yy – Yellow yy - Green

Three different Genotypes but Two Colors. Why? YY – Yellow Yy – Yellow yy - Green Dominant Allele – rep. by a capital letter – Y Recessive Allele – rep. by a lowercase letter - y Dominant Alleles OVER POWER Recessive Alleles

YY – Homozygous Yellow Yy – Heterozygous Yellow yy – Homozygous Green

How do alleles pass from parent to child? Punnett Squares What if you cross a Homozygous Yellow Pea (YY) with a Homozygous Green Pea (yy)? 100% Heterozygous Yellow Peas

25% Homozygous Yellow 50% Heterozygous Yellow 25% Homozygous Green