<span>Carbon dioxide is a colorless and odorless gas that is vital to life on Earth. This naturally occurring chemical compound is made up of a carbon atom covalently double bonded to two oxygen atoms. Carbon dioxide exists in Earth's atmosphere as a trace gas at a concentration of about 0.04 percent by volume. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, in ice caps and glaciers and also in seawater. It is present in deposits of petroleum and natural gas.</span>
Radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.
<span>The correct answer is the chromatin. The chromosomes of all organisms, excluding bacteria, are made of chromatin. Chromatin is a group of macromolecules consisting of RNA, DNA, and protein.</span>
