Approximately one billion oxygen molecules. that is because there are about 250 million molecules of haemoglobin in each cell, and each haemoglobin molecule binds to 4 oxygen molecules
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
Here are the answers.
1. Runoff from the land in a <em>stream’s watershed</em>……….
2. And water from its <em>tributaries</em>.
3. At the stream’s headwaters, the <em>gradient</em>………..
4. The greater the water speed, the larger the <em>stream load</em>………..
5. Which is made up of: a) <em>suspended load</em>, b) <em>dissolved load</em>, c) <em>bed load</em>
6. Under these conditions a <em>braided stream</em> may form
7. Where gradient flattens, a <em>meander</em> may form
