If the farmer increased the carbon dioxide level from 2800 to 4500 ppm what would be the increase in the rate of photosynthesis?

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?

If animal agriculture was eliminated, how much grain would become available for human consumption?

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.