Date Class
21. What is the main role of carbon dioxide during the process of photosynthesis?
a. Carbon dioxide is a waste product that is released into the atmosphere.
b. Carbon dioxide is used to assemble sugars, the main product of
photosynthesis.
C. Carbon dioxide is used to accept electrons and transfer them between
photosystems.
d. Carbon dioxide is used to transfer energy from the light-dependent reactions
to the light-independent reactions.

What is a difference between systemic and pulmonary circulation? a. systemic circulation carries oxygenated blood to the lungs and pulmonary circulation carries deoxygenated blood to the body. b. systemic circulation carries deoxygenated blood to the lungs and pulmonary circulation carries oxygenated blood to the body. c. systemic circulation carries deoxygenated blood to the body and pulmonary circulation carries oxygenated blood to the lungs. d. systemic circulation carries oxygenated blood to the body and pulmonary circulation carries deoxygenated blood to the lungs.