Science Olympiad Heredity Practice Test

The term 'homozygous' refers to a genetic condition where an organism possesses two identical alleles for a specific gene. This means that both copies of the gene inherited from each parent are the same, which can influence various traits depending on what those alleles express. For example, if a plant has a homozygous genotype for flower color where both alleles are for red flowers, it will consistently produce red flowers, as there is no variation between the alleles. In contrast, possessing two different alleles would indicate a heterozygous condition, while having one allele or no alleles present does not apply in standard genetic inheritance scenarios, as all organisms typically inherit alleles from their parents. Therefore, homozygosity ensures that the trait associated with that gene is expressed in a uniform manner, leading to predictable outcomes in offspring if both parents are homozygous for the same trait.