Neurotransmitters is the word you're looking for.
Consumer takes energy away
Production of the mature sperm cells have 4 step process beginning at puberty and throughout the male's lifetime. Spermiogenesis is the final process for production of sperm where the spermatids mature into motile spermatozoa. For humans, the spermatogenesis takes 74 days to 120 days and if the transport on the ductal system is included it would take 3 months.
A planarian can regrow any missing body part. Truth be told, in the event that you take a planarian and excise it into a few little pieces, every last one of those body sections can recover into an entirely different worm.
