Chapter 11.2 (Pg. 313-318): Applying Mendel’s Principles

Genetics Vocabulary- Genotype

- An organism’s genetic makeup

- Phenotype- An organism’s physical traits

- Homozygous- An organism has two of the

same allele for a trait

- Heterozygous- An organism has two different

alleles for a trait

Probability and Genetics- Probability is the likelihood an

event will occur

- Can be predicted in genetics through segregation

- Assumes that each gamete has a ½ chance of carrying an allele

Punnett Squares- Are named for their creator,

Reginald Punnett

- Are a simple matrix to calculate the probability of inheritance outcomes

- Show the possible genotypes and phenotypes of offspring

The Principle of Independent Assortment- Genes for different traits can

segregate independently during formation of gametes

- Traits that segregate independently do not influence each other’s inheritance

- The gene that determines seed shape does not affect gene for seed color

Two-Factor Crosses- Show how the alleles for one

trait are inherited independently of another trait

- Two dominant alleles don’t always stay together

- Trick is to show the correct combinations of alleles in the parents