Where do cells get the chemicals needed to synthesize other molecules?

Some Chemicals simply pass through the cell membrane. Other chemical pass through membranes attached to the cell membrane which allows specific types of Chemical through and block others. The chemicals are either blocked or allowed through based on the shape of the molecule.

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms