Final answer:
Parental, non-crossover gametes refer to gametes that carry the original combinations of alleles from the parents, indicating the absence of genetic recombination, and thereby representing gametes without genetic variation.
Step-by-step explanation:
Parental, non-crossover gametes (non-recombinant) refer to gametes without genetic variation resulting from recombination events during meiosis. These gametes reflect the original combinations of alleles present in the parents, as opposed to recombinant gametes, which contain a mix of maternal and paternal alleles due to crossover events. During meiosis, specifically prophase I, crossover events occur and create genetic variation by swapping DNA segments between non-sister chromatids of homologous chromosomes. As a result, recombinant chromatids that contain a novel combination of alleles are formed. However, parental non-recombinant gametes maintain the unchanged allelic combination, similar to the genetic makeup of the parents, and therefore bypass any genetic recombination that contributes to genetic diversity.