The carbon-14 isotope is important because it allows scientists to determine the of an organic sample

Which organelle releases chemicals that break down large food particles into smaller ones?

Solutions to environmental problems in europe must

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