1846-1910

Belgian cytologist whose research helped explain how cells divide and distribute chromosomes equally to daughter cells. He was one of several scientists who determined that chromosomes duplicate by longitudinal splitting during the process of cell division. Van Beneden discovered that all individuals within a given species have a fixed number of chromosomes. He also demonstrated that egg and sperm cells are haploid (they contain half the number of chromosomes as body cells) and that fertilization reinstates the diploid state.