Convection occurs over a very very long time in the earth's mantle. Rock slowly gets melted down from the core, then shoots back up from volcanoes. The new rocks get buried by sand and sediments, and the process resets.
The troposphere is B.The stratosphere is A.The mesosphere is C.The thermosphere is D.
Answer:
Carbohydrates, Nucleic acids, Proteins, and Lipids
A carbohydrate is a biological molecule consisting of carbon, hydrogen and oxygen atoms, usually with a hydrogen–oxygen atom ratio of 2:1.
Nucleic acids are bio-polymers, or large bio-molecules, essential for all known forms of life.
Proteins are large bio-molecules, or macro-molecules, consisting of one or more long chains of amino acid residues.
In biology, lipids comprise a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, triglycerides, phospholipids, and others.
Explanation:
