Question 1

Not all molecules contain the same amount of chemical energy. The energy relationship between G33P and CO2 is

Accepted Answer

A)   G3P and CO2 have the same amount of energy.
B)   G3P has less energy than CO2.
C)   Neither G3P nor CO2 contain any chemical energy.
D)   G3P has more energy than CO2.

Question 2

The innermost compartment of a chloroplast formed by the interconnected thylakoids is the

Accepted Answer

A)   stroma.
B)   thylakoid membrane.
C)   chlorophyll.
D)   thylakoid space.
E)   leaf space.

Question 3

What of the following is a disadvantage of C4 photosynthesis relative to C3 photosynthesis?

Accepted Answer

A)   inability of rubisco to obtain O2
B)   need for energy to move fixed carbon in C4 compound into bundle sheath cells
C)   need for stomata to close to conserve H2O
D)   need for energy to move H2O into bundle sheath cells
E)   inability of ATP synthase to utilize H+ gradient for energy

Question 4

Which of the following correctly describes CO2 fixation in a C3 plant?

Accepted Answer

A)   Rubisco combines CO2 with RuBP to form a 6-carbon compound that then breaks down into two 3-carbon compounds.
B)   Rubisco combines CO2 with a 2-carbon compound to form G3P.
C)   Rubisco combines CO2 with a 2-carbon compound to form 3PG, which is then reduced to G3P.
D)   Rubisco combines 6 CO2 molecules to form RuBP, which breaks down into two 3-carbon compounds.
E)   Rubisco combines 3 CO2 molecules to form 3PG, which is then reduced to G3P. A

Question 5

As climate change leads to drier and drier summers in the southeastern U.S., more and more homeowners find that they have crabgrass growing in their yards. The reason for this is that

Accepted Answer

A)   Crabgrass is a type of cactus, so it grows better in dry climates.
B)   As the climate changes, homeowners are not caring for their yards as well.
C)   Crabgrass is a tropical plant that likes hot, dry climates.
D)   Crabgrass is a type of C3 plant that does well in dry climates.
E)   Crabgrass is a type of C4 plant that does well in dry climates.

Question 6

The light reactions produce __________, which are used in the Calvin cycle. The Calvin cycle produces __________, which are in turn used in the light reactions.

Accepted Answer

A)   ATP and NADPH; ADP and NADP
B)   CO2 and H2O; glucose and O2
C)   ATP and CO2; glucose and O2
D)   glucose and O2; CO2 and H2O
E)   ADP and NADH; ATP and NADPH

Question 7

A poison that disrupts the H+ gradient in the thylakoid space would most likely cause which of the following to accumulate during the Calvin cycle reactions?

Accepted Answer

A)   3-phosphoglycerate (3PG) 
B)   ribulose 1,5-bisphosphate (RuBP) 
C)   glyceraldehyde-3-phosphate (G3P) 
D)   NADPH
E)   1,3 bisphosphoglycerate (BPG)

Question 8

In photosynthesis, the light reactions ____________ while the Calvin cycle ____________.

Accepted Answer

A)   capture solar energy; converts the captured energy to chemical potential energy
B)   can occur only in the light; can occur only in the dark
C)   require the presence of ATP; makes ATP
D)   can only function if the stomata are open; can only occur if the stomata are closed
E)   use products manufactured in the dark reactions; creates products used in the dark reactions

Question 9

How does ATP synthase obtain the energy to produce ATP?

Accepted Answer

A)   Hydrogen ions flow down a concentration gradient from the thylakoid space to the stroma through ATP synthase, releasing energy that can be used to produce ATP from ADP + Pi.
B)   Water splits, releasing electrons that flow from the stroma to the thylakoid space and attach to the active site of ATP synthase.
C)   Electrons from the reaction site center of photosystem II are funneled to ATP synthase, which uses the energy to produce ATP from ADP + Pi.
D)   Hydrogen ions in the thylakoid space combine with electrons from the stroma at ATP synthase, releasing energy that can be used to produce ATP from ADP + Pi.
E)   A hydrogen ion from NADPH is used by ATP synthase to power the production of ATP from ADP + Pi, and an electron is released, splitting water.

Question 10

CAM photosynthesis limits CO2 fixation to nighttime hours in order to

Accepted Answer

A)   allow water to enter leaf spaces during the daylight hours.
B)   open stomata only at night, limiting water loss because of heat and low humidity.
C)   allow NADPH and ATP to enter leaf spaces.
D)   limit the Calvin cycle reactions to nighttime only.
E)   limit water uptake from the soil during daytime hours.

Question 11

A coenzyme is defined as

Accepted Answer

A)   a non-protein helper that works with an enzyme.
B)   another enzyme that assists an enzyme with a chemical reaction.
C)   another enzyme in the same biochemical pathway.
D)   a carbohydrate that assists an enzyme.
E)   a protein that is not an enzyme.

Question 12

The end product of the Calvin cycle reactions is ___________.

Accepted Answer

A)   glucose
B)   glyceraldehyde-3-phosphate (G3P) 
C)   sucrose
D)   3-phosphoglycerate (3PG) 
E)   ribulose 1,5-bisphosphate (RuBP)

Question 13

Which of the labeled cells of a C3 leaf does not perform photosynthesis?

Accepted Answer

A)   A and B
B)   A and D
C)   B and D
D)   B and C
E)   C and D B

Question 14

In C4 plants, chloroplasts are located

Accepted Answer

A)   in mesophyll cells.
B)   in the stomata.
C)   in both mesophyll and bundle sheath cells.
D)   in bundle sheath cells.
E)   in epidermal cells of the leaf.

Question 15

In C4 plants, the light reactions will stop during the daytime when the supply of what compound is limited?

Accepted Answer

A)   chlorophyll a
B)   NADP+
C)   H2O
D)   CO2
E)   O2

Question 16

In a redox reaction, reduction means _________, and oxidation means _________.

Accepted Answer

A)   loss of electrons; gain of electrons
B)   gain of water; loss of water
C)   gain of electrons; loss of electrons
D)   loss of water; gain of water
E)   gain of protons; loss of protons

Question 17

ATP synthase derives energy for the generation of ATP from

Accepted Answer

A)   The movement of hydrogen ions against their concentration gradient into the thylakoid space.
B)   The splitting of H2O which releases electrons.
C)   Solar energy captured by the light reactions changing the shape of the enzyme.
D)   Electrons transferred from NADPH causing the enzyme to change shape.
E)   The movement of hydrogen ions down their concentration gradient from the thylakoid space to the stroma.

Question 18

The light reactions of photosynthesis are said to be similar to a battery because they form a current. In which direction do the electrons of this circuit flow?

Accepted Answer

A)   H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH
B)   H2O → PSII → chlorophyll b → PSI → chlorophyll a → NADPH
C)   NADPH → PSII → electron transport chain → PSI → electron transport chain → NADP+
D)   NADP+ → PSII → electron transport chain → PSI → electron transport chain → NADPH
E)   PSI → electron transport chain → PSII → electron transport chain → NADPH

Question 19

The difference between bundle sheath cells in C3 and C4 plants is that

Accepted Answer

A)   the bundle sheath cells in C3 plants have chloroplasts while those in C4 plants do not.
B)   the bundle sheath cells in C4 plants have chloroplasts while those in C3 plants do not.
C)   the bundle sheath cells in C3 plants are arranged in columns just beneath the upper epidermis while those in C4 plants are arranged in a ring around veins.
D)   the bundle sheath cells in C4 plants are arranged in columns just beneath the upper epidermis while those in C3 plants are arranged in a ring around veins.
E)   There is no difference in bundle sheath cells in C3 and C4 plants. B

Question 20

Carotenoids are found in high concentrations in yellow and orange leaves or vegetables. This color is seen because the carotenoid pigments

Accepted Answer

A)   Reflect and transmit yellow and orange wavelengths of light.
B)   Absorb yellow and orange wavelengths of light.
C)   Absorb or transmit yellow and orange wavelengths of light.
D)   Absorb or reflect yellow and orange wavelengths of light.
E)   Absorb all wavelengths of light and then transmit yellow and orange wavelengths.

Exam 6: Energy for Life

Not all molecules contain the same amount of chemical energy. The energy relationship between G33P and CO2 is

Correct AnswerverifiedShow Answer

The innermost compartment of a chloroplast formed by the interconnected thylakoids is the

Correct AnswerverifiedShow Answer

What of the following is a disadvantage of C4 photosynthesis relative to C3 photosynthesis?

Correct AnswerverifiedShow Answer

Which of the following correctly describes CO2 fixation in a C3 plant?

Correct AnswerverifiedA

As climate change leads to drier and drier summers in the southeastern U.S., more and more homeowners find that they have crabgrass growing in their yards. The reason for this is that

Correct AnswerverifiedShow Answer

The light reactions produce __________, which are used in the Calvin cycle. The Calvin cycle produces __________, which are in turn used in the light reactions.

Correct AnswerverifiedShow Answer

A poison that disrupts the H+ gradient in the thylakoid space would most likely cause which of the following to accumulate during the Calvin cycle reactions?

Correct AnswerverifiedShow Answer

In photosynthesis, the light reactions ____________ while the Calvin cycle ____________.

Correct AnswerverifiedShow Answer

How does ATP synthase obtain the energy to produce ATP?

Correct AnswerverifiedShow Answer

CAM photosynthesis limits CO2 fixation to nighttime hours in order to

Correct AnswerverifiedShow Answer

A coenzyme is defined as

Correct AnswerverifiedShow Answer

The end product of the Calvin cycle reactions is ___________.

Correct AnswerverifiedShow Answer

Which of the labeled cells of a C3 leaf does not perform photosynthesis?

Correct AnswerverifiedB

In C4 plants, chloroplasts are located

Correct AnswerverifiedShow Answer

In C4 plants, the light reactions will stop during the daytime when the supply of what compound is limited?

Correct AnswerverifiedShow Answer

In a redox reaction, reduction means _________, and oxidation means _________.

Correct AnswerverifiedShow Answer

ATP synthase derives energy for the generation of ATP from

Correct AnswerverifiedShow Answer

The light reactions of photosynthesis are said to be similar to a battery because they form a current. In which direction do the electrons of this circuit flow?

Correct AnswerverifiedShow Answer

The difference between bundle sheath cells in C3 and C4 plants is that

Correct AnswerverifiedB

Carotenoids are found in high concentrations in yellow and orange leaves or vegetables. This color is seen because the carotenoid pigments

Correct AnswerverifiedShow Answer

Not all molecules contain the same amount of chemical energy. The energy relationship between G33P and CO₂ is

Correct Answer
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Which of the following correctly describes CO₂ fixation in a C3 plant?

Correct Answer
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A

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The light reactions produce , which are used in the Calvin cycle. The Calvin cycle produces , which are in turn used in the light reactions.

Correct Answer
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A poison that disrupts the H⁺ gradient in the thylakoid space would most likely cause which of the following to accumulate during the Calvin cycle reactions?

Correct Answer
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In photosynthesis, the light reactions while the Calvin cycle .

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CAM photosynthesis limits CO₂ fixation to nighttime hours in order to

Correct Answer
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B

In C₄ plants, chloroplasts are located

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In a redox reaction, reduction means _, and oxidation means _.

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The difference between bundle sheath cells in C₃ and C₄ plants is that

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B

Correct Answer
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