1. 11-2 Probability and Punnett Squares
Biology - Block 3
Pgs

2. Genetics and Probability
Probability – is the likelihood or chance that something is going to happen.
The principles of probability can be used to predict the outcomes of genetic crosses.

3. Punnett Squares
Illustrates possible gene combinations from a particular cross.
Used to predict and compare genetic variations that will result from the cross.

4. Phenotype Phenotype are the physical characteristics of an organism.
Ex: tall, curly hair, brown eyes, has dimples.

5. Genotype
This is the genetic makeup of an organism. Always expressed using 2 letters.
Can be expressed as homozygous or heterozygous.
Ex: HH, Gg, aa

6. Homozygous vs heterozygous – description of a genotype.
Homozygous – organism with two identical alleles.
Also called pure.
Ex: HH, bb
Heterozygous – organism with two different alleles.
Also called hybrid.
Ex: Aa, Gg