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.
Yes, a vegan diet can be challenging when it comes to avoiding goitrogenic foods, but so long as you minimize or thoroughly cook the major culprits (crucifers, millet, soy, etc.) and steer towards protein-rich plant foods not listed in the article (nuts, for example?), you can reduce risk to your thyroid gland.