AP BIOLOGY

Detailed explanation-1: -Through photosynthesis, humans can again breathe in the oxygen that was produced and survive. Photosynthesis and respiration are the two essential processes that allow life to sustain on earth.

Detailed explanation-2: -Trees do the opposite. So they take in what you exhaled, they take in carbon dioxide and they give out oxygen. And this is during the day. So during the day they take in carbon dioxide and they release oxygen.

Detailed explanation-3: -Plants breathe in oxygen and give out carbon dioxide. But during the day, the amount of carbon dioxide released is much less than the amount required for photosynthesis. So, plants take in carbon dioxide from the atmosphere for preparing food.

Detailed explanation-4: -Simplified, we breathe in oxygen and carbon dioxide out, and plants do the opposite. We breathe in and out through our mouths but how do plants breathe? Plants also have mouths. The green parts of land plants are covered with tiny units called stomata, which is Greek for mouths.