Drag the tiles to the correct boxes to complete the pairs. Before the presence of living organisms, Earth was a very different place. Match each fact about Precambrian Earth to the sphere most affected by it.

Tiles:
- Cyanobacteria began to emerge as a life-form.
- Oceans contained far less salt than they do today.
- Oxygen spilled into this sphere from ocean waters.
- Oxidation in rocks and minerals was not possible.

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?

it's c.us forest service