homozygous recessive
Both alleles (factors) for a trait are the same and recessive (aa)
Homozygous recessive refers to an individual who has two copies of the same recessive allele for a particular gene. This means that both the mother and the father have contributed the same recessive gene to the offspring.
If an individual is homozygous recessive for a particular trait, it means that they express that trait exclusively since they do not have any dominant alleles to mask the recessive trait. For instance, if we consider a pea plant gene for flower color, the allele for purple flowers is dominantly expressed over the allele for white flowers. Therefore, if an individual inherits one dominant allele and one recessive allele, their flower color would still be purple. However, if they inherit two copies of the recessive allele, their flowers would be white since there is no dominant allele to mask the expression of the recessive allele.
Therefore, if an individual is homozygous recessive for a particular trait, they will only express the phenotype associated with that recessive allele and not the dominant allele.
More Answers:
Alleles: The Role They Play in Genetics and InheritanceHeterozygous: Genetic Variations for Increased Diversity
Homozygous Dominant: How Genetics Determine Trait Expression