Question

What would happen to life on earth if the rates of photosynthesis and cellular respiration in all phototrophs were equal?

Answer 1

Plants hold extra sugar to get them through the night. If all rates were equal they would not have the excess sugar to help them survive the cold weather. This however is a far reaching question and would not happen, making my answer hypothetical.

Answer 2

Answer:

When the level of release of carbon dioxide during respiration and use of carbon dioxide during photosynthesis this results in a compensation point. At compensation point the net available carbon dioxide to phototrophs becomes  zero. As, carbon dioxide is the chief ingredient for photosynthetic products like glucose and oxygen. These products are used up during the process of respiration. When the rates of two processes photosynthesis and respiration becomes equal. Phototrophic organisms will not be able to compensate for lack of carbon dioxide levels. Phototrophs will not be able to produce their food in the form of glucose and hence will not be able to respire too. This will result in lack of overall available food from phototrophs and lack of available oxygen for respiration. This will result in decline of organisms on earth.