What does it mean if an organism is described as homozygous?

When an organism is described as homozygous, it means that it has identical gene pairs for a particular trait or characteristic. This can occur when an organism inherits the same allele from both parents for that specific gene. For instance, in a plant that is homozygous for flower color, it might have two alleles for purple flowers, one from each parent, leading to consistent expression of that trait in its offspring.

Choosing this option highlights the genetic stability of homozygous organisms, often the result of selective breeding processes where certain traits are desired, leading to purebred cultivars that express specific characteristics predictably. This is important in agricultural practices, as it ensures uniformity in crops or livestock breeding.

The other concepts mentioned do not align with the definition of homozygosity. Different gene pairs would indicate heterozygosity, while hybrid vigor refers to the phenomenon where hybrids (heterozygous organisms) show improved or stronger traits compared to their homozygous parents. Being a purebred organism often implies homozygosity, but it is a broader term that can include other genetic configurations.