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.

21. D.

Explanation:

I don't know what light-dependent and independents are, but I know the others are wrong.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c