Genotype, Phenotype, & Punnett Squares

A genotype is the genetic makeup of an organism, represented by the alleles it possesses (e.g., AA, Aa, aa).

A phenotype is the observable physical or biochemical characteristics of an organism, determined by its genotype and environment.

A dominant allele is an allele that expresses its trait even when only one copy is present in the genotype.

A recessive allele is an allele that only expresses its trait when two copies are present in the genotype.

The dominant allele is expressed in the phenotype.

A Punnett square is a diagram used to predict the genetic outcomes of a cross between two organisms.

The phenotype will be green seeds.

The probability is 25%.

An organism is homozygous if it has two identical alleles for a particular trait (e.g., AA or aa).

An organism is heterozygous if it has two different alleles for a particular trait (e.g., Aa).