Deck 7: Photosynthesis

Question 1

Photorespiration occurs mainly in:

A)C₃ plants.
B)C₄ plants.
C)CAM plants.
D)all of the above.

Answer 1

A

Question 2

Which is most closely associated with the Calvin cycle?

A)ATP production
B)oxygen production
C)carbon dioxide fixation
D)carbon dioxide production
E)removal of electrons from water for passage through an electron transport system

Answer 2

C

Question 3

immediately becomes a six-carbon sugar that is the base for starch,sucrose,cellulose,etc.

Answer 3

False

Question 4

_______ is a product of the Calvin Cycle that is used to form glucose phosphate,amino acids or fatty acids.

A)ATP.
B)ribulose bisphosphate (RuBP).
C)glyceraldehyde-3-phospate (G3P).
D)PEP carboxylase (PEPcase).
E)carbon dioxide.

Question 5

decreases cell carbon dioxide levels,which increases the diffusion gradient.

Question 6

What structure is required for an organism to be classified as an autotroph?

A)chloroplast
B)mitochondria
C)nucleus
D)Golgi Body

Question 7

Protons (H⁺)accumulate in the thylakoid space during electron transport between photosystems I and II.The excess of protons in the thylakoid space

A)enters the photorespiration pathway.
B)converts NADP to NADPH and generates ATP in the process.
C)is small enough to diffuse back out through the lipid bilayer.
D)raises the pH of the space until the processes stop.
E)moves from the thylakoid space to the stroma through an ATP synthase complex channel that generates ATP.

Question 8

Which statement is NOT true about the noncyclic electron pathway?

A)Electrons are boosted to higher energy level in Photosystem I.
B)Sunlight excites electrons in Photosystem II.
C)It produces ATP.
D)It produces NADPH.
E)It produces carbohydrates through carbon dioxide fixation.

Question 9

To what does the term stroma refer?

A)the double membrane of the chloroplast
B)a flattened disk or sac in the chloroplast
C)a stack of thylakoid membrane structures
D)the central fluid-filled space of the chloroplast
E)the cytochrome system in the membranes of the thylakoids

Question 10

If plants were only able to undergo the cyclic pathway,which of the following would NOT be true?

A)Plants would not produce oxygen.
B)Carbohydrate could still be produced but in much smaller quantities.
C)More NADPH would be produced during the cyclic electron pathway.
D)ATP production would decrease due to a smaller amount of H⁺ being available.

Question 11

Which of these is NOT a major photosynthetic pigment in plants?

A)chlorophyll a
B)chlorophyll b
C)chlorophyll c
D)carotenoid pigments

Question 12

To what does the term grana refer?

A)the double membrane of the chloroplast
B)a flattened disk or sac in the chloroplast
C)a stack of thylakoid membrane structures
D)the central fluid-filled space of the chloroplast
E)the cytochrome system in the membranes of the thylakoids

Question 13

What are the end products of photosynthesis?

A)water and carbon dioxide
B)water and oxygen
C)oxygen and carbohydrate
D)carbohydrate and water

Question 14

The major enzyme that 'fixes' carbon dioxide is called

A)ribulose bisphosphate carboxylase (rubisco).
B)glyceraldehyde-3-phospate (G3P).
C)PEP carboxylase (PEPcase).
D)lactate dehydrogenase.

Question 15

forms a six-carbon molecule that immediately breaks down into two three-carbon PGA molecules.

Question 16

Why are plants green?

A)They absorb only green wavelengths of light.
B)They absorb only yellow and blue wavelengths of light.
C)They reflect nearly all wavelengths of light.
D)They reflect green wavelengths of light and absorb blue and red light.
E)They reflect yellow and blue wavelengths of light.

Question 17

Which statement is NOT true about photosystems?

A)Photosystem I passes electrons on to Photosystem II.
B)Each photosystem contains numerous pigment molecules that act as antennas to capture light.
C)Photosystem I contains a reaction center molecule that loses electrons which are then replaced by electrons from water.
D)Electrons in the reaction center molecule are excited by absorbed solar energy and are passed along to an acceptor molecule.

Question 18

What organisms are capable of photosynthesis?

A)plants only
B)plants and algae only
C)plants and some bacteria only
D)plants,algae,and some bacteria

Question 19

When the stomata in a leaf close during the day,then

A)carbon dioxide in the air spaces in the leaf decreases.
B)oxygen in the air spaces in the leaf increases.
C)C₃ plants carry on photorespiration,using O₂ and producing PGA and CO₂.
D)all photosystems as well as photorespiration come to a halt.
E)All choices but the halting of photosystems are correct.

Question 20

is a reaction assisted by large quantities of RuBP carboxylase enzyme.

Question 21

Oxygen production in photosynthesis involves all of the following EXCEPT

A)photosystem one.
B)photosystem two.
C)splitting of water.
D)light reactions.

Question 22

The light-dependent reactions of photosynthesis occur in the stroma of the chloroplast.

Question 23

Characterize the reactions involved in these reactions of the Calvin Cycle.

A)These are reactions involved in the regeneration of RuBP.The reactions include an exergonic reaction (ATP à ADP)and the reduction of the coenzyme NADPH.
B)These reactions are involved in the reduction of CO₂.Energy is required in the form of ATP,which is hydrolyzed to ADP.The substrate BPG is reduced,while the coenzyme NADPH is oxidized.
C)These reactions are involved in the fixation of CO_2. Energy is required in the form of ADP,which is hydrolyzed to ATP.The substrate BPG is oxidized,while the coenzyme NADPH is reduced.
D)These reactions are part of Light Reactions in noncyclic pathway.ATP and NADPH are used during these reactions.

Question 24

Photorespiration is the process by which light is used to release the stored energy in carbohydrate molecules to perform all work in plant cells.

Question 25

Plants that conduct C-4 metabolism are desert plants.

Question 26

During the light reactions what structure is responsible for absorbing the solar energy?

A)chloroplast
B)stroma
C)stoma
D)bark of the tree

Question 27

A product of photosynthesis,__________,is the chief source of energy for most organisms.

A)Oxygen
B)Sucrose
C)Glucose
D)All of the above

Question 28

Which of the following pairs is correct?

A)C₄ plants = bundle sheath cells contain chlorophyll
B)C₃ plants = bundle sheath cells contain chlorophyll
C)CAM plants = epidermal cells that contain chlorophyll
D)C₄ plants = stoma that contain chlorophyll

Question 29

When an electron has been excited to a higher energy state,it can then drop back to the original level,re-emitting the light as fluorescence.When chlorophyll is extracted in solution,and a bright red or blue light is shown on it,the chlorophyll fluoresces brightly.However,when the chlorophyll is packaged inside chloroplasts and the red or blue light is turned on,there is no fluorescence.This most likely indicates that

A)the red and blue light waves are reflected by the chlorophyll membrane.
B)chlorophyll in solution is a different molecule than chlorophyll in a chloroplast.
C)excited electrons are transferred to electron acceptors in the chloroplast.
D)fluorescence does not work in living cells.
E)green light must be used to make living cells fluoresce.

Question 30

Fossil fuels are full of energy stored from photosynthesis millions of years ago.

Question 31

Which of the following plants is an example of a CAM plant?

A)cactus
B)corn
C)rice
D)wheat
E)oak tree

Question 32

Phosphoenylpyruvate carboxylase (PEPCase)fixes carbon dioxide(C₁)to PEP(C₃)to form oxaloacetate(C₄)within mesophyll cells of the C-4 plants.

Question 33

Chemiosmotic ATP synthesis occurs in the cytosol of the cell.

Question 34

The action spectrum of photosynthesis shows a high light absorption for violet/blue and orange/red and a low absorption for green/yellow.If we were to set up an experiment where narrow bands of unicolored light were shown on an aquatic plant such as Elodea,and we counted the number of bubbles of oxygen produced as an indicator of photosynthetic rate,how would the graph appear?

A)just like the action spectrum with peaks at violet/blue and orange/red and a trough at yellow/green
B)exactly inverted from the action spectrum with a peak for yellow/green
C)perfectly flat because many wavelengths are used by chlorophyll
D)a descending line because ultra-violet has more energy than infra-red
E)There is no way to guess without actually running the experiment.

Question 35

If the Calvin cycle uses three molecules of CO₂ to produce six molecules of G3P (glyceraldehydes-3-phosphate),but only one G3P molecule is used to form a carbohydrate molecule,what happens to the other carbons that were taken in?

A)Any unused CO₂ is released into the environment.
B)The other five G3P molecules are used to regenerate more RuBP.
C)Any unused G3P molecule is converted and stored as starch.
D)The remaining five G3P molecules are used to reduce CO₂.

Question 36

C-4 plants

A)store carbon dioxide temporarily as oxaloacetate.
B)are found in hot dry climates.
C)have a net photosynthetic rate two to three times that of C-3 plants.
D)All of the choices are correct.

Question 37

The function of sunlight in photosynthesis is to:

A)reduce NADPH to NADP
B)fix O₂ in the Calvin cycle
C)excite electrons in chlorophyll
D)combine carbon dioxide and water to form ATP and NADPH

Question 38

G3P (glyceraldehyde 3 phosphate)is used by plants for all of the following EXCEPT the formation of

A)fatty acids.
B)amino acids.
C)oxygen.
D)sucrose.

Question 39

An early experiment by Van Helmont (1600s)describes how he "grew a tree in a large pot and found that after five years,the amount of soil in the pot had not changed.He concluded that the increase in weight was due to the addition of water." At that time,the compounds in the air had not yet been identified.Today,you know that he only discovered half the story.Which additional experiment would provide evidence for the rest of the story?

A)A very careful audit of the water taken in and lost by the tree would have revealed only half the added weight gained by the tree.
B)Carbon is discovered as a major element in trees and is lacking in water molecules.
C)Radioactive carbon in CO₂ in the air is soon located as part of tree structures.
D)The critical experiment involves the conversion of nutrients in the soil.
E)All but the nutrient conversion is correct.

Question 40

While C-4 plants have carbon dioxide fixation and carbon dioxide uptake separated by location within the plant,CAM plants

A)have these processes separated by time.
B)fix much greater amounts of carbon dioxide than C-4 plants.
C)are found in tropical regions where nutrients are abundant.
D)All of the choices are correct.

Question 41

What is the ultimate destination for the energized electrons during the light reactions of photosynthesis?

A)they are taken up by NADP⁺ to produce NADPH
B)they are taken up by NADPH to produce NADP⁺
C)they are taken up by NADH to produce NAD⁺
D)they are taken up by NAD⁺ to produce NADH

Question 42

Which of the following statements about the Calvin cycle is correct?

A)the CO₂ is absorbed and reduced to CH₂O
B)the CO₂ is absorbed and reduced to C₂H₂O₂
C)the CO^- is absorbed and reduced to CH₂O
D)the CO₂ is absorbed and used to form ATP