Final answer:
To match the definitions with the terms: a. heterozygous, b. homozygous, c. alleles, d. dominant. Alleles are different versions of a gene, and whether an individual is homozygous or heterozygous for a trait depends on whether they posess the same or different alleles. Dominant alleles are expressed in both homozygous and heterozygous conditions, while recessive alleles are expressed only in the homozygous state.
Step-by-step explanation:
An allele is one of the different versions of a gene that determines a particular trait. Heterozygous genotypes are made up of two different alleles, while homozygous genotypes are made up of the same alleles. The genotype that is expressed only in the homozygous condition is called a recessive allele. Dominant alleles are expressed when there is only one allele present.
An allele is one of the different versions of a gene for a particular trait. When an individual has two copies of the same allele, they are homozygous for that gene. If the two alleles are different, the individual is heterozygous. The version of the allele that is expressed, regardless of whether it is paired with a different allele (heterozygous) or the same allele (homozygous), is called dominant. The recessive allele is expressed only when paired with another recessive allele in a homozygous condition. Understanding the concepts of alleles and how they determine genotypes is essential in genetics.