The definition of a concubine is a woman who is a mistress to a man with a wife or who cannot be married to her because of a difference in social status. An example of a concubine is one of the mistresses of an important king who has many wives and mistresses. concubine. concubine.
How do you identify a tree species? It is known that mature, leafy trees, such as redwoods, aspens and oaks, are the best producers of oxygen. Additionally, it is known that a tree produces higher volumes when growing than when mature, because converting air and soil into wood causes the tree to produce more oxygen.
Most of this oxygen comes from tiny ocean plants â called phytoplankton â that live near the waterâs surface and drift with the currents. Like all plants, they photosynthesize â that is, they use sunlight and carbon dioxide to make food. A byproduct of photosynthesis is oxygen. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earthâs atmosphere. They arenât sure because itâs a tough thing to calculate. In the lab, scientists can determine how much oxygen is produced by a single phytoplankton cell. The hard part is figuring out the total number of these microscopic plants throughout Earthâs oceans.