Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? See Concept 13.2 (Page) View Available Hint(s) Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? See Concept 13.2 (Page) They need meiosis if the cells are producing organs such as ovaries. They need only meiosis if they produce egg cells. They need both if they are producing plant gametes. They need only mitosis to make large numbers of cells such as sperm. A single-celled organism only needs mitosis.