The two principal gonadotropins in vertebrates are luteinizing hormone (LH) and follicle-stimulating hormone (FSH), although primates produce a third gonadotropin called chorionic gonadotropin (CG). LH and FSH are heterodimers consisting of two peptide chains, an alpha chain and a beta chain.H and FSH are secreted by the anterior pituitary gland, while hCG and eCG are secreted by the placenta in pregnant humans and mares, respectively. The gonadotropins act on the gonads, controlling gamete and sex hormone production.
Anything that can bring about a mutation in DNA is called a mutagen. Most mutagens fall into one of two categories: They are either a form of energy or a chemical. In addition to X rays, other forms of radiation that can cause mutagens include ultraviolet radiation, gamma rays, and ionizing radiation.
Mutations cause changes in the genetic code that lead to genetic variation and the potential to develop disease. Gene mutations can be generally categorized into two types: point mutations and base-pair insertions or deletions. Point mutations are the most common type of gene mutation.