In that circumstance, a normally functioning HIF pathway actually helps cancer cells survive their low-oxygen environment, and it encourages the formation of new blood vessels to feed the tumor.

These plants contribute significantly to air purification and oxygenation, but none can provide 24-hour oxygen continuously.

When blood returns to the heart, it follows a complicated pathway. If you were in the bloodstream, you would follow the steps below one by one. Oxygen-poor blood (shown in blue) flows from the ...

Without photosynthetic bacteria, the reliance that Earth's life has on oxygen may well have never happened, in addition to ...