Alarge research project was carried out in the oceans surrounding antarctica to learn whether adding iron-containing compounds to the iron-limited polar sea would enhance the growth of phytoplankton (small, free-floating photosynthetic organisms). this project was performed with the hope that if plankton growth were significantly increased over large areas, it might slow global warming. what is the basis for such an expectation?
a) the increased biomass would lead to decreased solar heating due to absorption of light by photosystems i and ii.
b) the increased biomass will lead to increased levels of atmospheric oxygen through photosynthesis.
c) the increased biomass will lead to decreased levels of atmospheric oxygen through respiration.
d) the increased biomass will act as a sponge (a carbon sink) for atmospheric carbon dioxide.

D) The increased biomass will act as a sponge (a carbon sink) for atmospheric carbon dioxide.

Explanation:

One of the main greenhouse gases is carbon dioxide. The amount of this gas in the atmosphere is related with global warming.

Since photosynthesis uses carbon dioxide and water to produce glucose, this carbon dioxide is taken from the atmosphere and then transformed and store in the bodies of phytoplankton. When the organisms die, they sink to the bottom where this carbon is store for several thousands of years. This effect may contribute to slow global warming.  

the scientific method.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.