Carbon is a major component of all organic compounds, including carbohydrates, lipids, proteins, and nucleic acids. Carbon dioxide is continually exchanged between the atmosphere and oceans. What geological process returns carbon to the atmosphere in the form of carbon dioxide?
A) respiration
B) transpiration
C) volcanic activity
D) decomposition of marine sediments

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

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.

What is the ecological role of food chains and food webs