Photosynthesis and cellular respiration are often described as existing in a cycle. Which statement best describes why this is true? O Plants perform only photosynthesis and animals perform cellular respiration
O Heterotrophs can perform photosynthesis and cellular respiration, where autotrophs can only perform photosynthesis.
O Plants perform only cellular respiration and animal perform photosynthesis.
O Each reaction results in chemical products that are needed as reactants for the other reaction.

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c. carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit