Missense, nonsense, and silent mutations are examples of which type of mutation?

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled

49 ! how are energy cycles and growth cycles related?

What type of cell division is used to replace old cell?