Probably the strongest biological oxidizing agent is P680+ because:
1. It accepts electron in both photosystems.
2. It transfers electrons to plastoquinone.
3. It strongly attracts electrons formed by the splitting of water.
4. It transfers electrons to plastocyanin.

The primary function of the Calvin cycle is to:
1. use ATP to release carbon dioxide
2. use NADPH to release carbon dioxide
3. split water and release oxygen
4. fix inorganic carbon to simple sugars

Which of the following must occur in the biochemical pathway of Calvin cycle?
1. addition of a pair of electrons from NADPH
2. inactivation of RuBP carboxylase enzyme
3. regeneration of ATP from ADP
4. regeneration of RuBP

Given below is the schematic diagram of Calvin cycle taking place in a certain plant. ATP used by this plant is radioactively labeled. One turn of the cycle is allowed to happen. Radioactivity would be seen in all except:

1. A
2. B
3. C and D
4. E

For the synthesis of glucose, the source of hydrogen atoms is:

The pathway shown in the figure will be seen in:

1. ${\mathrm{C}}_4$ plants
2. CAM plants
3. ${\mathrm{C}}_3$ plants
4. All photosynthetic plants

The process of photosynthesis has lower efficiency if photorespiration occurs because of the reduced formation of:

A ${\mathrm{C}}_3$ and a ${\mathrm{C}}_4$ plant were fed with carbon dioxide radioactively labeled with an isotope of carbon. In which of the following molecules, respectively in ${\mathrm{C}}_3$ and ${\mathrm{C}}_4$ plants, would radioactivity first appear as photosynthesis progresses?

The relationship between photosynthesis and respiration can be best described as:

The following diagram shows the ${\mathrm{C}}_4$ photosynthetic carbon cycle. A and B can respectively be:
   
1. Pyruvate; malate or aspartate
2. Phoshoglycerate; fumarate or aspartate
3. Phosphoenol pyruvate; malate or aspartate
4. Phosphoenol pyruvate; fumarate or aspartate