Punnett Squares

Capital letter, overrides recessive

Lowercase letter, only works when homozygous

One capital one lower / 2 different letters

Two lowercase / recessive letters

Two uppercase / dominant letters

Both alleles are expressed equally in the phenotype (AB)

Heterozygous phenotype is between two homozygous phenotypes. (Red x White = Pink)

More than two alleles for gene in a population.

Different versions of a gene

Observable characteristics of an organism

Genetic makeup of an organism

Observable characteristic of organism determined by genotype and environment

Location of gene on a chromosome

Two chromosomes in a pair – normally one inherited from the mother and one from the father

Offspring of two individuals with different genotypes

Organism that is homozygous at all genetic loci. (AA x AA)

Used to predict probability of offspring genotypes from parental genotypes in a genetic cross

Likelihood of an event occurring

Only possibility for offspring is heterozygous. (AA x aa)