1. Genetics The study of heredity
How traits are passed on from one generation to the next.

2. Blended Inheritance
In ancient times, people thought traits were an equal blend from each parent
Blue eyes + black eyes = green eyes
Could not explain
Brown eyes + Brown eyes = blue eyes

3. Gregor Mendel Austrian monk who studied garden peas
Determined the laws of heredity

4. Are some traits stronger than others?
Mendel crossed pea plants with different traits.
Parental(P) + Parental(P) = First Fillial(F1)
Yellow peas + Green peas = All Green
Round peas + Wrinkled peas = All Round

5. Parental
Generation
Green +
Yellow
Round
Wrinkled
First Fillial
All Green
All Round
Second Fillial

6. Are some traits stronger than others?
Results:
When plants with two different traits (alleles) are crossed, one trait appears in the offspring.
Dominant: Trait that appears always
Recessive: Trait that is hidden by dominant

7. Are the recessive traits gone in F1?
Mendel crossed the peas produced to see if the recessive (hidden) trait would appear.
F1 + F1 = F2
Green + Green = 3 Green to 1 yellow
Round + Round = 3 Round to 1 wrinkled

8. Parental
Generation
Green +
Yellow
Round
Wrinkled
First Fillial
Mendel bred these together
All Green
Green +Green
All Round
Round + Round
Second Fillial
This is the ratio
3 Green
1 Yellow
3 Round
1 Wrinkled

9. Are the recessive traits gone in F1?
Results
Recessive traits (alleles) are present in F1, just hidden.
Parents give alleles randomly to offspring.

10. The Law of Segregation Bb b B
Gametes get one copy of an allele pair from a parent. b Bb B
Parent Genes
Gametes
Round/wrinkled
wrinkled
Round

11. The Law of Independent Assortment
Genes for different traits segregate independently during gamete formation.

12. The Law of Independent Assortment
AaBb AB Ab aB ab
Parent Genotype
Gametes
Round/wrinkled
Green/yellow
yellow/wrinkled
Green/ Round
yellow/Round
Green/ wrinkled