Heterotrophs are organisms that consume other organisms in order to gain energy. Compare two different categories of heterotrophs in terms of how they obtain energy. Explain your answer in one to two sentences.(2 points)

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