What conditions and raw materials are necessary for photosynthesis to occur

Most of the carbon on earth is stored in the form of

About __ of the mass of the cell is water

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures