Its skin so it protects the internal organs and systems
Answer:
The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle. Respiration happens all the time, but dominates during the colder months of the year, resulting in higher CO2 levels in the atmosphere during those months.
Explanation:
- DNA and RNA are made up of monomers called nucleotides. - DNA and RNA both have 3 nitrogenous bases: Adenine, Cytosine and Guanine. - DNA and RNA both have a phosphate groups in their nucleotides. Sometimes called phosphoric acid.Feb 18, 2009