The energy releasing process that does not require oxygen is called anaerobic respiration<span>. This is mainly used by organisms who live in areas with little oxygen such as at the bottom of the ocean.</span>
According to the cell theory, the cell is the basic unit of life. All living organisms are composed of one or more cells. Based on the organization of their cellular structures, all living cells can be divided into two groups: prokaryotic and eukaryotic (also spelled procaryotic and eucaryotic).
1) climate change
2)pollution
3)invasive
4)overexplotution
5) deforestation and habit loss
Water will violently react to the alkali. All the alkali metals react directly with oxygen; lithium and sodium form monoxides, Li2O and Na2O, and the heavier alkali metals form superoxides, MO2.
