Chapter 13 - Photosynthesis

Photosynthesis can be divided into two steps: the light-dependent reactions and the Calvin cycle. Which of the following is true regarding these two steps?

• The light-dependent reactions use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight.

• The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.

• The Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.

• During the light-dependent reactions, carbon dioxide is fixed to produce sugars that form glucose.

Which of the following are true regarding photosynthesis and cellular respiration?

• Photosynthesis produces carbon dioxide, and cellular respiration uses carbon dioxide

• Photosynthesis and cellular respiration are performed by all plants and animals.

• Both photosynthesis and cellular respiration occur in the chloroplasts of a cell.

• Photosynthesis and cellular respiration are near-opposite processes.

Which of the following are the reactants for photosynthesis?

• oxygen, glucose

• water, glucose

• water, oxygen

• water, carbon dioxide

The light-dependent reactions of photosynthesis take energy from sunlight and convert it into stored chemical energy. Which compounds are produced in the light-dependent reactions?

• ATP and NADPH

• ATP and NADP+

• ADP and NADPH

• ADP and NADP+

Which of the following explains what happens to oxygen produced by the light-dependent reactions?

• It is used in the Calvin cycle.

• It is released into the atmosphere.

• It combines with NADPH to produce water.

• It is recycled as a reactant in another light-dependent reaction.

Why does chlorophyll look green to the human eye?

• Chlorophyll reflects green light.

• Chlorophyll is green as the result of an optical illusion created by light transmission.

• Chlorophyll absorbs green light.

• Chlorophyll absorbs blue and yellow light, which make green.

The thylakoid membrane becomes damaged, causing the inside of the thylakoid to mix with the stroma. Which of the following processes is likely to be most affected by this damage?

• The reduction of NADP+ to NADPH

• Sunlight absorption by the chloroplasts

• The movement of electrons from photosystem II (PSII) to photosystem I (PSI)

• ATP synthesis

A mutation occurs in the chloroplasts of a lettuce plant, causing its thylakoid membranes to become more permeable to charged ions. How might this mutation affect the Calvin cycle?

• Fewer carbohydrates would be produced by the Calvin cycle.

• There would be no change to the Calvin cycle.

• More carbohydrates would be produced by Calvin cycle.

Which of the following combinations is not reactants in the Calvin cycle?

• ATP and reduced NADP

• Triose phosphate and carbon dioxide

• RuBP and GP

• ATP and rubisco

The Calvin cycle is considered light-independent because it can occur in darkness. However, most often the Calvin cycle takes place in sunlight. Which of the following likely explains why?

• The enzymes involved in the Calvin cycle are unable to bind substrates in the dark.

• Sunlight is important in activating carbon fixation in the Calvin cycle.

• The Calvin cycle requires ATP and NADPH, which require sunlight to be produced.

• RuBP regeneration requires sunlight in order to occur and continue the Calvin cycle.