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.
A vegan diet consists of plant-based foods only. In other words, vegans do not consume any meat or dairy products. A vegan diet is formed on the basis of a food pyramid different from that of a conventional meat-based diet. Thus, from bottom to top the vegan food pyramid includes grains, legumes and nuts, vegetables, fruits, and fats.