Explain how humans obtain the energy and matter they need in order to survive. HINT: Think about the chemical bonds and what happens to atoms in your body.

Which class of organic compounds makes up the channels and pumps that move materials from one side of the cell membrane to the other? a.) carbohydrates b.) lipids c.) proteins d.) nucleic acids

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

How does secondary succession differ from primary succession?