why do some species employ both mitosis and meiosis, whereas other species use only mitosis?why do some species employ both mitosis and meiosis, whereas other species use only mitosis?if they produce large numbers of sperm cells they do not require meiosisthey need meiosis if the cells are producing organs such as ovariesif they produce egg cells they do not require mitosisa single-celled organism only needs mitosisthey need both if they are reproducing sexually