male and female, n.All

Male and female (n.) are ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠late arrivals: in many one-celled creatures two perfectly similar individuals unite and neither can be called either.