Download Pea In Your Genes

Pea In Your Genes
Gregor Mendel
• Liked to play with pea plants.
• Noticed that certain
Characteristics
(inheritable physical
features) showed up or
disappeared in peas.
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
Genotype
• YY – Yellow
• Yy – Yellow
• yy - Green
Phenotype
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