21) The light reactions occur in the:

A) mitochondrial membrane.

B) thylakoid membrane.

C) stoma.

D) thylakoid compartment.

E) mitochondrial compartment.

22) Which of the following statements about photosynthesis is false?

A) Sunlight excites electrons from chlorophyll, which are captured by ATP.

B) In the light reactions, electrons eventually wind up on NADPH.

C) Photosynthesis involves many redox reactions similar to the electron transport chain used during cellular respiration.

D) During the light reactions, ATP and NADPH are synthesized.

E) A waste product of the light reactions is O2.

23) What is the primary purpose of the light reactions of photosynthesis?

A) to produce glucose

B) to create oxygen gas

C) to release electrons needed to convert solar energy to chemical energy

D) to remove carbon dioxide gas from the atmosphere

24) The absorption of light energy by a photosystem:

A) transfers an electron from a reaction center to accessory pigment molecules.

B) causes electrons to be transferred from NADP+ to a reaction center.

C) boosts electrons to a higher energy level.

D) causes electrons to lose energy until they reach the reaction center.

25) Both photosynthesis and cellular respiration rely on electron carrier molecules to provide electrons to ultimately help produce ATP. In photosynthesis, the source of electrons is ________ and in cellular respiration the source of electrons is ________.

A) carbon dioxide; oxygen

B) glucose; oxygen

C) oxygen; carbon dioxide

D) water; glucose

26) The oxygen produced during photosynthesis comes from:

A) water.

B) carbohydrates.

C) carbon dioxide.

D) the air plants take in.

27) The splitting of water in photosynthesis provides:

A) CO2 and electrons.

B) O2 and electrons.

C) glucose and electrons.

D) hydrogen ions and light energy.

28) Chloroplasts transform ________ energy into the ________ energy of ATP.

A) heat; light

B) light; heat

C) heat; chemical

D) light; chemical

E) chemical; heat

29) During the light reactions of photosynthesis, which of these does not occur?

A) Water is used to regenerate the electrons in the chlorophyll that were excited by sunlight.

B) Sunlight excites electrons in chlorophyll, which are transferred directly to ATP.

C) Sunlight excites electrons in chlorophyll, allowing an electron acceptor up the energy hill to accept them.

D) Sunlight excites electrons in chlorophyll, which eventually wind up on NADPH.

30) The products of the light reactions that are then used by the Calvin cycle are:

A) ATP and NADPH.

B) ADP and NADP+.

C) ATP and O2.

D) O2 and NADPH.

E) ATP and CO2.