Click Reset and Return to original settings. Suppose we completely stopped burning fossil fuels immediately. How many years would it take to return to atmospheric CO2 levels from the year 1800, about 600 GtC? Use the Gizmo to find the answer.

What is one way in which a discovery that is made by using cell technology could change existing scientific knowledge? a. a discovery could lead to a change in experimental methods. b. a discovery could lead to a replacement of a scientific theory. c. a discovery could lead to a new brand of cell culture medium. d. a discovery could lead to a new material for culture flasks.

Explain how organisms could be harmed by high levels of salt from roadways?

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