1. Probability and Genetics

2. Probability The likelihood that a particular event will occur.
Example: Coin Toss
1 in 2
50%

3. Mendel and Probability
Crossing two hybrids (Bb)
¾ had purple flowers
¼ of the plants had white flowers
Percentages?

4. Genotypes VS. Phenotype
A phenotype describes an organisms physical traits or appearance.
Example: brown hair
A genotype is the genetic make up of the organism;
what type of alleles are present.
Examples: TT, Tt, or tt

5. Review An organisms physical appearance is known as: Genotype Hybrid
Genetics
Phenotype

6. Homozygous vs. Heterozygous
“homo” means the same
Homozygous- both alleles are the same. (purebred)
Examples:
TT- homozygous dominant
tt- homozygous recessive
“hetero” means different
Heterozygous- the alleles are different (hybrid)
Examples:
Tt- heterozygous

7. Homozygous or Heterozygous?Bb
Heterozygous MM
Homozygous dominant mm
Homozygous recessive Mn

8. Review Another name for heterozygous is… Purebred Homozygous Hybrid
Phenotype

9. Mouse Genetics

10. Punnett Squares A Punnett Square is a
chart that shows all of the possible outcomes of a genetic cross
The allele that each parent will pass on is based on chance

11. Punnett Square Practice
Get out a piece of paper and let’s practice using a Punnett square.