Final answer:
Positive interference, a phenomenon where a chromosome crossover prevents additional crossovers in nearby regions, is indeed true. This impacts genetic diversity by affecting the likelihood of further crossover events during meiosis, which promotes genetic recombination.
Step-by-step explanation:
The statement that positive interference occurs when a crossover in one region of a chromosome interferes with crossovers in nearby regions is true. Interference refers to the phenomenon where the occurrence of a crossover in one portion of a chromosome reduces the probability of crossovers in adjacent segments. This can impact the genetic variation produced during meiosis because crossovers are a source of genetic recombination which reshuffles alleles and provides the diversity needed for evolution and adaptation.
It is important to note that chromosomal crossover usually occurs during meiosis, specifically in the first division of meiosis when homologous chromosomes pair up and exchange segments of their DNA. This can result in chromosomes with a mix of paternal and maternal genes, which are then passed on to offspring. The crossover between chromosomes is not random; it is more likely to occur between genes that are farther apart, which makes recombination between them more frequent, contrary to genes that are close together.