Por que las plantas tienen la capacidad de reproducirse a partir de un tallo

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

What kinds of molecules can pass through the cell membrane without any problem?

All of these things can block a bronchus and cause collapse of a lung except