The chemical reaction for photosynthesis is 6CO2+ 12H2O+ Light Energy -> C6H12O6 + 6O2 + 6H2O. If the input water is labeled with a radioactive isotope of oxygen, 18 O. then the oxygen gas released as the reaction proceeds is also labeled with 18 O. Which of the following is the most likely explanation?

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.

Which of these is an example of land degradation? a. containers designed to store pollutants leak. b. fertilizers provide too many nutrients to crops. c. garbage is buried so the land can be reclaimed later. d. a drought kills all the plants in an area, leaving bare land

Describe characteristics of a good respitory surface