AP Biology Photosynthesis Test

In chloroplasts, ATP is synthesized from ADP plus inorganic phosphate (Pi) in a reaction catalyzed by ATP synthase molecules that are embedded in the thylakoid membrane. Which of the following statements provides evidence to support the claim that no ATP will be synthesized in the absence of a proton gradient across the thylakoid membrane? a. Blocking electron flow from one carrier to the next in the electron transport chains blocks formation of a proton gradient in the thylakoid. b. Increasing the proton concentration difference across the thylakoid membrane is not associated with a parallel increase in the rate of ATP synthesis c. NO ATP is synthesized when channel proteins that allow the free passage of protons are inserted into the thylakoid membrane.

c. NO ATP is synthesized when channel proteins that allow the free passage of protons are inserted into the thylakoid membrane.

What most likely causes the trends in oxygen concentration? a. The water becomes colder at night and thus holds more oxygen b. Respiration in most organisms increases at night c. More organisms are respiring at night than during the day. d. Photosynthesis produces more oxygen than is consumed by respiration during the day.

d. Photosynthesis produces more oxygen than is consumed by respiration during the day.

The energy required to run the Calvin cycle reactions of photosynthesis comes from which two substances produced during the light-dependent reactions? a. ATP and NADPH b. ADP and PO4 c. O2 and CO2 d. H2O and CO2

a. ATP and NADPH

Which of the following questions is most relevant to understanding the Calvin cycle? a. How does chlorophyll capture light? b. How is ATP used in the formation of 3-carbon carbohydrates? c. How is NADP+ reduced to NADPH?

b. How is ATP used in the formation of 3-carbon carbohydrates?

The rate of oxygen production equaled the rate of oxygen consumption during which of the following time periods? a. G to H b. C to H c. J to K d. G to J

c. J to K

Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because a. yellow-leaved seedlings were unable to absorb water from the paper towels b. taller green-leaved seedlings blocked the light and prevented photosynthesis c. yellow-leaved seedlings were unable to convert light energy to chemical energy

c. yellow-leaved seedlings were unable to convert light energy to chemical energy

Process in which O2 is released as a by-product of oxidation-reduction reactions a. Glycolysis b. Krebs Cycle c. Calvin Cycle d. Light dependent reactions of photosynthesis

d. Light dependent reactions of photosynthesis

The O2 released during photosynthesis comes from a. Co2 b. H2O c. O2

b. H2O

Based on the data shown, changes in the light intensity resulted in changes in the rate of which of the following processes? a. Excretion b. Photosynthesis c. Respiration d. Translation

b. Photosynthesis

The carbon 'that makes up organic molecules in plants is derived directly from... a. combustion of fuels b. carbon fixed in photosynthesis c. carbon dioxide produced in respiration d. carbon in the lithosphere

b. carbon fixed in photosynthesis

Carbohydrate-synthesizing reactions of photosynthesis directly require a. light b. products of the light reactions c. darkness d. O2 and H2O

b. products of the light reactions

Process in which carbon from CO2 is incorporated into organic molecules a. Glycolysis b. Krebs Cycle c. Calvin Cycle

c. Calvin Cycle (light independent reactions)

Which of the following is an important difference between light-dependent and light-independent reactions of photosynthesis? a. The light-dependent reactions occur only during the day; the light-independent reactions occur only during the night. b. The light-dependent reactions occur in the cytoplasm; the light-independent reactions occur in chloroplasts. c. The light-dependent reactions utilize CO2 and H2O; the light-independent reactions produce CO2and H2O. d. The light-dependent reactions depend on the presence of both photosystems I and II; the light-independent reactions require only photosystem I. e. The light-dependent reactions produce ATP and NADPH; the light-independent reactions use energy stored in ATP and NADPH.

e. The light-dependent reactions produce ATP and NADPH; the light-independent reactions use energy stored in ATP and NADPH.

Which of the following statements is true about the Krebs (citric acid) cycle and the Calvin (light-independent) cycle? a. They both result in a net production of ATP and NADH. b. They both require a net input of ATP. c. They both result in a release of oxygen. d. They both take place within the cytoplasmic matrix. e. They both are carried out by enzymes located within an organelle matrix.

e. They both are carried out by enzymes located within an organelle matrix.

An increase in the rate of oxygen production by algae would be accompanied by a comparable increase in the rate of production of which of the following substances? a. C6H12O6 b. CO2 c. CH4 d. H2O

a. C6H12O6

According to the results of this experiment, germination of tobacco seeds during the first week is a. increased by exposure to light b. unaffected by light intensity c. prevented by paper towels d. accelerated in green-leaved seedlings

a. increased by exposure to light

To test the hypothesis that a particular plant synthesizes storage lipids by using glyceraldehyde 3-phosphate (G3P) from photosynthesis, a researcher plans to use radiolabeled precursors to track the molecules through the biosynthetic pathway. Which of the following radiolabeled precursors is most appropriate for the researcher to use? a. 15N-labeled N2, because atmospheric nitrogen is fixed to amino acids by photosynthesis b. 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis c. 35S-labeled methionine, because amino acids are incorporated into lipids during photosynthesis

b. 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis

The chemical reaction for photosynthesis is 6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 + 6 H2O If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation? a. During the light reactions of photosynthesis, water is split, the hydrogen atoms combine with the CO2, and oxygen gas is released. b. During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.

b. During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.

A scientist claims that Elysia chlorotica, a species of sea slug, is capable of photosynthesis. Which of the following observations provides the best evidence to support the claim? a. Elysia chlorotica will die if not exposed to light. b. Elysia chlorotica grows when exposed to light in the absence of other food sources. c. Elysia chlorotica grows faster when exposed to light than when placed in the dark.

b. Elysia chlorotica grows when exposed to light in the absence of other food sources.

A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants. a. Atmospheric carbon dioxide is produced by the burning of fossil fuels, which are formed from the remains of living organisms such as plants. b. Atmospheric carbon dioxide is produced by the burning of fossil fuels, which are formed from the remains of living organisms such as plants. c. Atmospheric carbon dioxide typically enters plant leaves through stomata, which plants rely on for regulating gas exchange with the atmosphere. d. Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.

d. Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.