Are organisms that derive carbon from organic compounds. heterotrophs autotrophs phototrophs chemotrophs

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

Which of the following types of reactions would decrease the entropy within a cell? a. dehydration reaction, b. hydrolysis, c. respiration, d. digestion, e. catabolism.

Ascientist publishes a paper that states the changes in the levels of gases in the atmosphere of a moon of saturn indicate that there may be terrestrial life on the moon. which statement correctly answers whether the question of alien life on this moon is scientific?