Sexual reproduction with fertilization (most often found in nature, most eukaryotes are characteristic).
Sexual reproduction without fertilization – parthenogenesis (characteristic of bees, ants, aphids, lizards), from an unfertilized egg.
Hermaphrodism (flat and annelids, mollusks).
Conjugation (the simplest primitive form characteristic of bacteria, some algae).
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.