Well, without medical care humans would literally die of so many infections and diseases, we would already be on the brink of extinction. Think of the Ebola outbreak, the black flu, Hiv's. Without the help of medical care, we would not be able to sufficiently prevent sickness.<span />
Answer:
The major reason is an increased blood flow to the stomach and intestines (due to the extra work because of the food), and blood being drawn away from the brain, hence decreasing the amount of oxygen being sent to our brain, and making us drowsy.
Explanation:
Hope this helped!
The oxygen in the upper atmosphere combine to form ozone layer (o3) that allows to colonize surface water.
Explanation:
The fossil stomatolites are formed at about 3.0 ga laminated bacteria. they form the sediments to fall into a thin film of bacteria, these bacteria binds with the sediment and grows through it.
Cynobacteria uses water, CO2 and sunlight to create their own food and produce oxygen as a by product. The significance of stromatolites is that they are earliest fossil evidence life on earth.
They were first organism to photosynthesis and produce oxygen.
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