1. Law of Independent Assortment
Mendel & Heredity
Law of Independent Assortment

2. Law of Independent Assortment
Genes for different traits on the same chromosome are inherited independently from each other
Mendel discovered this through his experiments w/dihybrid crosses (2 parents w/2 different traits)
Ex: tall, yellow pea plant with a short, green pea plant

3. Dihybrid cross – like a puzzle
Can 2 parents with Heterozygous round, yellow seeds produce offspring with wrinkled, green seeds?
1st – determine possible gametes/ allele partners
First
Outside
Inside
Last
Set up PSq
boxes

6. Practice Dihybrid Cross
Heterozygous Purple Flower & Homozygous Tall X
Homozygous white flower & Heterozygous Tall
Key: F purple flower T tall
f white flower t short

7. Environment affects gene expression
Internal - Age, gender (hormonal differences)
Ex: male bird feathers colorful
External - Temperature, nutrition, light, radiation, chemicals, viruses
Ex: genes for height; without proper nutrition…will not be tall