Crossing-over in meiosis is typically described as a random event and for genes that reside on most areas of the chromosomes this is a true statement. However, it is observed that the crossing-over process becomes suppressed as one examines genes that lie progressively closer to the centromere (i.e., that region of the chromosome where sister chromatids remain attached until the onset of Anaphase II). Consider four genes in a heterozygotous state that lie on the same chromosome prior to the onset of meiosis.