Genotype with same alleles
Allele
Homozygous
Heterozygous
Dominant
Recessive
A genotype with the same alleles can be either homozygous or heterozygous.
Homozygous: This means that both alleles of a particular gene are the same. For example, if an organism has two copies of the dominant allele for a certain trait, its genotype would be homozygous dominant (e.g., AA). Similarly, if an organism has two copies of the recessive allele for a certain trait, its genotype would be homozygous recessive (e.g., aa).
Heterozygous: This means that an organism has two different alleles for a particular gene. For example, if an organism has one copy of the dominant allele and one copy of the recessive allele for a certain trait, its genotype would be heterozygous (e.g., Aa).
Dominant: The dominant allele is the allele that is expressed in the phenotype of an organism, regardless of whether it is homozygous dominant or heterozygous.
Recessive: The recessive allele is the allele that is only expressed in the phenotype of an organism if it is homozygous recessive.