Final answer:
A person with two of the same gene from each parent is 'homozygous' for a genetic trait. Homozygous individuals have identical alleles, which can be either dominant or recessive. Meanwhile, 'heterozygous' individuals have two different alleles for a trait.
Step-by-step explanation:
A person who has two of the same gene, one received from each parent, is said to be homozygous for a certain genetic trait. Being homozygous means that the individual has identical alleles on both homologous chromosomes, which could be either dominant or recessive.
If the alleles are dominant, the dominant trait will be expressed, likewise, if they are recessive, the recessive trait will be expressed. The opposite condition is heterozygous, where the individual has two different alleles for the gene.
For instance, regarding blood types, an individual may inherit two 'A' alleles resulting in a genotype of AA, or two 'O' alleles as OO, both are homozygous genotypes. However, if they have one 'A' allele and one 'B' allele, their genotype is AB, which is heterozygous.