Chiasma (genetics) In genetics, a chiasma (pl. chiasmata) is the point of contact, the physical link, between two (non-sister) chromatids belonging to homologous chromosomes. At a given chiasma, an exchange of genetic material can occur between both chromatids, what is called a chromosomal crossover, but this is much more frequent during meiosis than mitosis. In meiosis, absence of a chiasma usually result in improper chromosomal segregation and aneuploidy.
A cancer prevention diet is one that is high in fiber, low in fat (especially animal fat), and includes generous portions of fruits and vegetables. It also minimizes or excludes alcohol. The best diets are pure vegetarian diets.
Balancing a raw food diet. Melina, who's been on a high raw diet for six years and has competed in triathlons annually since turning 60, recommends people on uncooked vegan diets take vitamin B12 supplements. The lack of it raises something called homocysteine, and that increases your risk of heart disease.