Define each of the following terms:

allele

Key Concepts

Allele

An allele is a variant form of a gene that arises by mutation and is found at the same place on a chromosome. Alleles can be dominant or recessive, influencing the expression of traits in an organism. For example, in pea plants, the allele for purple flowers is dominant over the allele for white flowers, determining the flower color of the plant.

Genotype

The genotype refers to the genetic constitution of an individual, specifically the alleles present at a given locus. It determines the potential traits an organism can express, although the actual expression may be influenced by environmental factors. For instance, a plant with a genotype of 'PP' or 'Pp' will exhibit the dominant trait, while 'pp' will show the recessive trait.

Phenotype

The phenotype is the observable physical or biochemical characteristics of an organism, determined by both its genotype and environmental influences. It includes traits such as color, shape, and behavior. For example, two plants with the same genotype may have different phenotypes if they are grown in different environmental conditions, such as light or soil quality.