1. Genetic Crosses

2. Genotype/Phenotype Genotype Phenotype Genetic make-up of an organism
Example= TT, Tt, tt
Phenotype
Appearance of an organism
Example= Tall or short, Red hair or black hair

3. Probability Probability Likelihood that a specific event will occur
May be expressed as a decimal, fraction, or percentage
Example: Dice probability lab

4. Alleles For each trait, there is a dominant and a recessive allele.
The dominant trait is represented by a capital letter and recessive by a lower case letter
Alleles can be represented by any letter. Capitalization is all that matters.
Three possible genotypes in organisms:
AA=homozygous dominant
Aa=heterozygous
aa=homozygous recessive

5. Allelic Frequencies Homozygous Heterozygous
Describes an individual that has identical alleles for a trait on both homologous chromosomes
Homozygous dominant=TT
Homozygous recessive=tt
Heterozygous
Describes an individual that has two different alleles for a trait
Example= Tt

6. Monohybrid Crosses Monohybrid Cross Punnett Square Test Cross
Cross between individuals that involves one pair of contrasting traits
Punnett Square
Technique that can be used to predict the outcome of genetic crosses
Test Cross
An individual with an unknown genotype is crossed with a homozygous recessive individual

7. Punnett Square Crosses

8. Dominance Complete Dominance Incomplete Dominance Codominance
Occurs when heterozygous individuals and dominant homozygous individuals are impossible to tell apart in phenotype
Incomplete Dominance
Occurs when two or more alleles influence the phenotype and results in a phenotype intermediate between the dominant trait and the recessive trait
Codominance
Occurs when both alleles for a gene are expressed in a heterozygous offspring

9. Dihybrid Cross Dihybrid Cross
Cross in which two characteristic traits are tracked