Deck 10: Photosynthesis

Question 1

As a research scientist,you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour.You find 30 000 molecules of ATP consumed,but only 20 000 molecules of NADPH.Where did the extra ATP molecules come from?

A)photosystem II
B)photosystem I
C)cyclic electron flow
D)linear electron flow
E)chlorophyll

Answer 1

C

Question 2

Which of the following are directly associated with photosystem I?

A)harvesting of light energy by ATP
B)receiving electrons from the thylakoid membrane electron transport chain
C)generation of molecular oxygen
D)extraction of hydrogen electrons from the splitting of water
E)passing electrons to the thylakoid membrane electron transport chain

Answer 2

B

Question 3

What does the chemiosmotic process in chloroplasts involve?

A)establishment of a proton gradient across the thylakoid membrane
B)diffusion of electrons through the thylakoid membrane
C)reduction of water to produce ATP energy
D)movement of water by osmosis into the thylakoid space from the stroma
E)formation of glucose, using carbon dioxide, NADPH, and ATP

Answer 3

A

Question 4

In autotrophic bacteria,where are the enzymes located that can carry on carbon fixation (reduction of carbon dioxide to carbohydrate)?

A)in chloroplast membranes
B)in chloroplast stroma
C)in the cytosol
D)in the nucleoid
E)in the infolded plasma membrane

Question 5

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma.This damage will have the most direct effect on which of the following processes?

A)the splitting of water
B)the absorption of light energy by chlorophyll
C)the flow of electrons from photosystem II to photosystem I
D)the synthesis of ATP
E)the reduction of NADP⁺

Question 6

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

A)CO₂ and glucose
B)H₂O and O₂
C)ADP,℗ ᵢ, and NADP⁺
D)electrons and H⁺
E)ATP and NADPH

Question 7

Which statement describes the functioning of photosystem II?

A)Light energy excites electrons in the thylakoid membrane electron transport chain.
B)Photons are passed along to a reaction-centre chlorophyll.
C)The P680 chlorophyll donates a pair of protons to NADP⁺, which is thus converted to NADPH.
D)The electron vacancies in P680⁺ are filled by electrons derived from water.
E)The splitting of water yields molecular carbon dioxide as a by-product.

Question 8

A plant has a unique photosynthetic pigment.The leaves of this plant appear to be reddish yellow.What wavelengths of visible light are being absorbed by this pigment?

A)red and yellow
B)blue and violet
C)green and yellow
D)blue, green, and red
E)green, blue, and yellow

Question 9

In a plant cell,where are the ATP synthase complexes located?

A)thylakoid membrane only
B)plasma membrane only
C)inner mitochondrial membrane only
D)thylakoid membrane and inner mitochondrial membrane
E)thylakoid membrane and plasma membrane

Question 10

If photosynthesizing green algae are provided with CO₂ synthesized with heavy oxygen (¹⁸O),later analysis will show that all but one of the following compounds produced by the algae contain the ¹⁸O label.That one is

A)3-phosphoglycerate.
B)glyceraldehyde 3-phosphate (G3P).
C)glucose.
D)ribulose bisphosphate (RuBP).
E)O₂.

Question 11

Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution.What would be likely to happen?

A)The isolated chloroplasts will make ATP.
B)The Calvin cycle will be activated.
C)Cyclic photophosphorylation will occur.
D)The isolated chloroplasts will generate oxygen gas.
E)The isolated chloroplasts will reduce NADP⁺ to NADPH.

Question 12

Which of the following best describes decomposers?

A)They are autotrophs that feed off of organic litter.
B)They are autotrophs that decompose inorganic litter.
C)They are heterotrophs that obtain nutrition from items such as leaves.
D)They are heterotrophs that obtain nutrition from light.
E)They are producers that obtain nutrition from decomposition.

Question 13

Some photosynthetic organisms contain chloroplasts that lack photosystem II,yet are able to survive.The best way to detect the lack of photosystem II in these organisms would be

A)to determine if they have thylakoids in the chloroplasts.
B)to test for liberation of O₂ in the light.
C)to test for CO₂ fixation in the dark.
D)to do experiments to generate an action spectrum.
E)to test for production of either sucrose or starch.

Question 14

What are the products of linear photophosphorylation?

A)heat and fluorescence
B)ATP and P700
C)ATP and NADPH
D)ADP and NADP
E)P700 and P680

Question 15

In the thylakoid membranes,what is the main role of the antenna pigment molecules?

A)split water and release oxygen to the reaction-centre chlorophyll
B)harvest photons and transfer light energy to the reaction-centre chlorophyll
C)synthesize ATP from ADP and ᵢ
D)transfer electrons to ferredoxin and then NADPH
E)concentrate photons within the stroma

Question 16

When oxygen is released as a result of photosynthesis,it is a direct by-product of

A)reducing NADP⁺.
B)splitting water molecules.
C)chemiosmosis.
D)the electron transfer system of photosystem I.
E)the electron transfer system of photosystem II.

Question 17

Where does the Calvin cycle take place?

A)stroma of the chloroplast
B)thylakoid membrane
C)cytoplasm surrounding the chloroplast
D)interior of the thylakoid (thylakoid space)
E)outer membrane of the chloroplast

Question 18

In any ecosystem,terrestrial or aquatic,what group(s)is (are)always necessary?

A)autotrophs and heterotrophs
B)producers and primary consumers
C)photosynthesizers
D)autotrophs
E)green plants

Question 19

Which of the events listed below occurs in the light reactions of photosynthesis?

A)NADP is produced.
B)NADPH is reduced to NADP⁺.
C)Carbon dioxide is incorporated into 3-phosphoglycerate.
D)ATP is phosphorylated to yield ADP.
E)Light is absorbed and funnelled to reaction-centre chlorophyll a.

Question 20

Halobacterium has a photosynthetic membrane that is coloured purple.Its photosynthetic action spectrum is exactly complementary (opposite to)the action spectrum for green plants.What wavelengths of light do the Halobacterium photosynthetic pigments absorb?

A)red and yellow
B)blue, green, and red
C)green and yellow
D)red and green
E)blue and red

Question 21

Where are the molecules of the photosynthetic electron transport chain found in plant cells?

A)thylakoid membranes of chloroplasts
B)stroma of chloroplasts
C)outer membrane of mitochondria
D)matrix of mitochondria
E)cytoplasm

Question 22

The reactions that produce molecular oxygen (O)take place in

A)the light reactions alone.
B)the Calvin cycle alone.
C)both the light reactions and the Calvin cycle.
D)neither the light reactions nor the Calvin cycle.
E)the chloroplast, but are not part of photosynthesis.

Question 23

In C₃ photosynthesis,the reactions that require ATP take place in

A)the light reactions alone.
B)the Calvin cycle alone.
C)both the light reactions and the Calvin cycle.
D)neither the light reactions nor the Calvin cycle.
E)the chloroplast, but are not part of photosynthesis.

Question 24

Which of the following statements best describes the relationship between photosynthesis and respiration?

A)Respiration runs the biochemical pathways of photosynthesis in reverse.
B)Photosynthesis stores energy in complex organic molecules, whereas respiration releases it.
C)Photosynthesis occurs only in plants and respiration occurs only in animals.
D)ATP molecules are produced in photosynthesis and used up in respiration.
E)Respiration is anabolic and photosynthesis is catabolic.

Question 25

The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during

A)photosynthesis.
B)respiration.
C)both photosynthesis and respiration.
D)neither photosynthesis nor respiration.
E)photorespiration.

Question 26

In photosynthetic cells,synthesis of ATP by the chemiosmotic mechanism occurs during

A)photosynthesis only.
B)respiration only.
C)both photosynthesis and respiration.
D)neither photosynthesis nor respiration.
E)photorespiration only.

Question 27

Some photosynthetic bacteria (e.g.,purple sulphur bacteria)have only photosystem I,whereas others (e.g.,cyanobacteria)have both photosystem I and photosystem II.Which of the following might this observation imply?

A)Photosystem II was selected against in some species.
B)Photosynthesis with only photosystem I is more ancestral.
C)Photosystem II may have evolved to be more photoprotective.
D)Linear electron flow is more primitive than cyclic flow of electrons.
E)Cyclic flow is more necessary than linear electron flow.

Question 28

In thylakoids,protons travel through ATP synthase from the thylakoid space to the stroma.Therefore,the catalytic "knobs" of ATP synthase would be located

A)on the side facing the thylakoid space.
B)on the ATP molecules themselves.
C)on the pigment molecules of photosystem I and photosystem II.
D)on the stromal side of the membrane.
E)built into the centre of the thylakoid stack (granum).

Question 29

P680⁺ is said to be the strongest biological oxidizing agent.Why?

A)It is the receptor for the most excited electron in either photosystem.
B)It is the molecule that transfers electrons to plastoquinone (Pq)of the electron transfer system.
C)It transfers its electrons to reduce NADP⁺ to NADPH.
D)This molecule has a stronger attraction for electrons than oxygen, to obtain electrons from water.
E)It has a positive charge.

Question 30

Generation of proton gradients across membranes occurs during

A)photosynthesis.
B)respiration.
C)both photosynthesis and respiration.
D)neither photosynthesis nor respiration.
E)photorespiration.

Question 31

What function do carotenoids have in plants?

A)They serve as accessory pigments to increase light absorption.
B)They protect against oxidative damage from excessive light energy.
C)They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation.
D)They reflect orange light and enhance red light absorption by chlorophyll.
E)They take up and remove toxins from the ground water.

Question 32

What is the primary function of the Calvin cycle?

A)use ATP to release carbon dioxide
B)use NADPH to release carbon dioxide
C)split water and release oxygen
D)transport RuBP out of the chloroplast
E)synthesize simple sugars from carbon dioxide

Question 33

What is the relationship between wavelength of light and the quantity of energy per photon?

A)They have a direct, linear relationship.
B)They are inversely related.
C)They are logarithmically related.
D)They are separate phenomena.
E)They are only related in certain parts of the spectrum.

Question 34

Where do the enzymatic reactions of the Calvin cycle take place?

A)stroma of the chloroplast
B)thylakoid membranes
C)matrix of the mitochondria
D)cytosol around the chloroplast
E)thylakoid space

Question 35

In chloroplasts,chemiosmosis translocates protons from

A)the stroma to the photosystem II.
B)the matrix to the stroma.
C)the stroma to the thylakoid space.
D)the intermembrane space to the matrix.
E)the thylakoid space to the stroma.

Question 36

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights,which are set to cycle between 12 hours of light and 12 hours of dark.The dissolved oxygen concentrations in both flasks are monitored.Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.

A)The dissolved oxygen in the flask with algae will always be higher.
B)The dissolved oxygen in the flask with algae will always be lower.
C)The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark.
D)The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.
E)The dissolved oxygen in the flask with algae will not be different from the control flask at any time.

Question 37

In metabolic processes of cell respiration and photosynthesis,what do the prosthetic groups such as heme and iron-sulphur complexes in components of the electron transport chain do?

A)donate electrons
B)act as reducing agents
C)act as oxidizing agents
D)transport protons within the mitochondria and chloroplasts
E)both oxidize and reduce during electron transport

Question 38

Reduction of NADP⁺ occurs during

A)photosynthesis.
B)respiration.
C)both photosynthesis and respiration.
D)neither photosynthesis nor respiration.
E)photorespiration.

Question 39

Cyclic electron flow may be photoprotective (protective to light-induced damage).Which of the following experiments could provide information on this phenomenon?

A)Use mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities against those of wild-type organisms.
B)Use plants that can carry out both linear and cyclic electron flow, or only one or another of these processes, and compare their light absorbance at different wavelengths and different light intensities.
C)Use bacteria that have only cyclic flow and look for their frequency of mutation damage at different light intensities.
D)Use bacteria with only cyclic flow and measure the number and types of photosynthetic pigments they have in their membranes.
E)Use plants with only photosystem I operative and measure how much damage occurs at different wavelengths.

Question 40

Reduction of oxygen to form water occurs during

A)photosynthesis only.
B)respiration only.
C)both photosynthesis and respiration.
D)neither photosynthesis nor respiration.
E)photorespiration only.

Question 41

According to the endosymbiotic theory,the original chloroplast was a

A)chemisynthetic archaea.
B)green algae.
C)purple sulphur bacteria.
D)mitochondria.
E)photosynthetic prokaryote.

Question 42

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

A)The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP,℗ ᵢ, and NADP⁺ to the light reactions.
B)The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions.
C)The light reactions supply the Calvin cycle with CO₂ to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP.
D)The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split.
E)There is no relationship between the light reactions and the Calvin cycle.

Question 43

Why are C₄ plants able to photosynthesize with no apparent photorespiration?

A)They do not participate in the Calvin cycle.
B)They use PEP carboxylase to initially fix CO₂.
C)They are adapted to cold, wet climates.
D)They conserve water more efficiently.
E)They exclude oxygen from their tissues.

Question 44

CAM plants keep stomata closed in daytime,thus reducing loss of water.They can do this because they

A)fix CO₂ into organic acids during the night.
B)fix CO₂ into sugars in the bundle-sheath cells.
C)fix CO₂ into pyruvate in the mesophyll cells.
D)use the enzyme phosphofructokinase, which outcompetes rubisco for CO₂.
E)use photosystem I and photosystem II at night.

Question 45

The NADPH required for the Calvin cycle comes from

A)reactions initiated in photosystem I.
B)reactions initiated in photosystem II.
C)the citric acid cycle.
D)glycolysis.
E)oxidative phosphorylation.

Question 46

Three "turns" of the Calvin cycle generate a "surplus" molecule of glyceraldehyde 3-phosphate (G3P).Which of the following is a consequence of this?

A)Formation of a molecule of glucose would require nine "turns."
B)G3P more readily forms sucrose and other disaccharides than it does monosaccharides.
C)Some plants would not taste sweet to us.
D)The formation of sucrose and starch in plants involves assembling G3P molecules, with or without further rearrangements.
E)Plants accumulate and store G3P.

Question 47

If plant gene alterations cause the plants to be deficient in photorespiration,what would most probably occur?

A)Photosynthetic efficiency would be reduced at low light intensities.
B)Cells would carry on the Calvin cycle at a much slower rate.
C)Less ATP would be generated.
D)There would be more light-induced damage to the cells.
E)Less oxygen would be produced.

Question 48

The alternative pathways of photosynthesis using the C₄ or CAM systems are said to be compromises.Why?

A)Each one minimizes both water loss and rate of photosynthesis.
B)C₄ compromises on water loss and CAM compromises on photorespiration.
C)Both minimize photorespiration but expend more ATP during carbon fixation.
D)CAM plants allow more water loss, while C₄ plants allow less CO₂ into the plant.
E)C₄ plants allow less water loss but CAM plants allow more water loss.

Question 49

The phylogenetic distribution of the enzyme Rubisco is limited to

A)C₃ plants only.
B)C₃ and C₄ plants.
C)all photosynthetic eukaryotes.
D)all known photoautotrophs, both bacterial and eukaryotic.
E)all living cells.

Question 50

Compared to C₃ plants,C₄ plants

A)can continue to fix CO₂ even at relatively low CO₂ concentrations and high oxygen concentrations.
B)have higher rates of photorespiration.
C)do not use rubisco for carbon fixation.
D)grow better under cool, moist conditions.
E)make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria.

Question 51

In an experiment studying photosynthesis performed during the day,you provide a plant with radioactive carbon (¹⁴C)dioxide as a metabolic tracer.The ¹⁴C is incorporated first into oxaloacetate.The plant is best characterized as a

A)C₄ plant.
B)C₃ plant.
C)CAM plant.
D)heterotroph.
E)chemoautotroph.

Question 52

If atmospheric CO₂ concentrations increase twofold or more,how will plants be affected,disregarding any changes in climate?

A)All plants will experience increased rates of photosynthesis.
B)C₃ plants will have faster growth; C₄ plants will be minimally affected.
C)C₄ plants will have faster growth; C₃ plants will be minimally affected.
D)C₃ plants will have faster growth; C₄ plants will have slower growth.
E)Plant growth will not be affected because atmospheric CO₂ concentrations are never limiting for plant growth.

Question 53

Photorespiration occurs when rubisco reacts RuBP with

A)CO₂.
B)O₂.
C)glyceraldehyde 3-phosphate.
D)3-phosphoglycerate.
E)NADPH.

Question 54

Where is the Calvin cycle located in a C₄ plant?

A)stems
B)bundle sheath cells
C)mesophyll cells
D)stomata
E)the chloroplasts in leaves

Question 55

The pH of the inner thylakoid space has been measured,as have the pH of the stroma and of the cytosol of a particular plant cell.Which,if any,relationship would you expect to find?

A)The pH within the thylakoid is less than that of the stroma.
B)The pH of the stroma is lower than that of the other two measurements.
C)The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol.
D)The pH of the thylakoid space is higher than that anywhere else in the cell.
E)There is no consistent relationship.

Question 56

Photorespiration lowers the efficiency of photosynthesis by

A)carbon dioxide molecules.
B)3-phosphoglycerate molecules.
C)ATP molecules.
D)ribulose bisphosphate molecules.
E)RuBP carboxylase molecules.

Question 57

Reactions that require CO₂ take place in

A)the light reactions alone.
B)the Calvin cycle alone.
C)both the light reactions and the Calvin cycle.
D)neither the light reactions nor the Calvin cycle.
E)the chloroplast, but are not part of photosynthesis.

Question 58

When do plants respire?

A)in the dark only.
B)in the light only.
C)both in light and dark.
D)never-they get their ATP from photophosphorylation.
E)only when excessive light energy induces photorespiration.

Question 59

In the process of carbon fixation,RuBP attaches a CO₂ to produce a six-carbon molecule,which is then split to produce two molecules of 3-phosphoglycerate.After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P),what more needs to happen to complete the Calvin cycle?

A)addition of a pair of electrons from NADPH
B)inactivation of RuBP carboxylase enzyme
C)regeneration of ATP from ADP
D)regeneration of RuBP
E)regeneration of NADP⁺

Question 60

In a plant leaf,the reactions that produce NADH occur in

A)the light reactions alone.
B)the Calvin cycle alone.
C)both the light reactions and the Calvin cycle.
D)neither the light reactions nor the Calvin cycle.
E)the chloroplast, but are not part of photosynthesis.

Question 61

Use the following figure and the compounds labelled A,B,C,D,and E to answer the following questions.

Which molecule(s)of the Calvin cycle is (are)also found in glycolysis?

A)B, C, E, and 3-phosphoglycerate
B)B, C, and E only
C)3-phosphoglycerate only
D)B, C, D, and 3-phosphoglycerate only
E)E only

Question 62

Use the following figure to answer the questions below.

What wavelength of light in the figure is most effective in driving photosynthesis?

A)420 mm
B)475 mm
C)575 mm
D)625 mm
E)730 mm

Question 63

If the process of photosynthesis had never evolved on Earth,this planet would

A)only contain anaerobic organisms.
B)have no land and be primarily ocean.
C)have no water and be dry land.
D)be very similar to the way it is today.
E)have no oxygen and thus no life.

Question 64

Use the following information to answer the questions below.
You have learned about research conducted during the 1930s by van Niel,who studied photosynthesis in bacteria,which were observed to not release O₂ even though they fixed CO₂.
From his experiments,van Niel concluded that

A)he must have done something wrong.
B)something else was being used to provide hydrogen.
C)CO₂ was not being split to produce O₂.
D)CO₂ was directly involved in O₂ production.
E)H₂O was being used to provide hydrogen.

Question 65

Use the following information to answer the questions below.
Theodor W.Engelmann illuminated a filament of algae with light that passed through a prism,thus exposing different segments of algae to different wavelengths of light.He added aerobic bacteria and then noted in which areas the bacteria congregated.He noted that the largest groups were found in the areas illuminated by the red and blue light.
What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

A)Bacteria released excess carbon dioxide in these areas.
B)Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
C)Bacteria congregated in these areas because these areas had the most oxygen being released.
D)Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.
E)Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.

Question 66

Use the following information to answer the questions below.
Theodor W.Engelmann illuminated a filament of algae with light that passed through a prism,thus exposing different segments of algae to different wavelengths of light.He added aerobic bacteria and then noted in which areas the bacteria congregated.He noted that the largest groups were found in the areas illuminated by the red and blue light.
An outcome of this experiment was to help determine

A)the relationship between heterotrophic and autotrophic organisms.
B)the relationship between wavelengths of light and the rate of aerobic respiration.
C)the relationship between wavelengths of light and the amount of heat released.
D)the relationship between wavelengths of light and the rate of photosynthesis.
E)the relationship between the concentration of carbon dioxide and the rate of photosynthesis.

Question 67

Use the following information to answer the questions below.
Theodor W.Engelmann illuminated a filament of algae with light that passed through a prism,thus exposing different segments of algae to different wavelengths of light.He added aerobic bacteria and then noted in which areas the bacteria congregated.He noted that the largest groups were found in the areas illuminated by the red and blue light.
If you ran the same experiment without passing light through a prism,what would you predict?

A)There would be no difference in results.
B)The bacteria would be relatively evenly distributed along the algal filaments.
C)The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
D)The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
E)The number of bacteria would decrease due to a decrease in the temperature of the water.

Question 68

Use the following figure to answer the questions below.

A gardener is concerned that her greenhouse is getting too hot from too much light,and seeks to shade her plants with coloured translucent plastic sheets.What colour should she use to reduce overall light energy,but still maximize plant growth?

A)green
B)blue
C)yellow
D)orange
E)Any colour will work equally well.

Question 69

Chemiosmosis in chloroplasts and mitochondria share all but one of the following conditions.

A)Iron-rich cytochrome is used for electron transport.
B)Electrons are passed through carriers that are progressively more electronegative.
C)Protons are pumped across a membrane into a reservoir.
D)An ATP synthase complex is embedded within the membrane.
E)Electrons are donated from organic compounds.

Question 70

Use the following figure and the compounds labelled A,B,C,D,and E to answer the following questions.

To identify the molecule that accepts CO₂,Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO₂ or cutting off light from cultures of photosynthetic algae.They then measured the concentrations of various metabolites immediately following the manipulation.How would these experiments help identify the CO₂ acceptor? Study the figure above to help you in determining the correct answer.

A)The CO₂ acceptor concentration would decrease when either the CO₂ or light are cut off.
B)The CO₂ acceptor concentration would increase when either the CO₂ or light are cut off.
C)The CO₂ acceptor concentration would increase when the CO₂ is cut off, but decrease when the light is cut off.
D)The CO₂ acceptor concentration would decrease when the CO₂ is cut off, but increase when the light is cut off.
E)The CO₂ acceptor concentration would stay the same regardless of the CO₂ or light.

Question 71

Use the following figure to answer the questions below.

Referring to the figure above,oxygen would inhibit the CO₂ fixation reactions in

A)cell I only.
B)cell II only.
C)neither cell I nor cell II.
D)both cell I and cell II.
E)cell I during the night and cell II during the day.

Question 72

Use the following figure to answer the questions below.

Which of the following statements is true concerning the figure above?

A)It represents cell processes involved in C₄ photosynthesis.
B)It represents the type of cell structures found in CAM plants.
C)It represents an adaptation that maximizes photorespiration.
D)It represents a C₃ photosynthetic system.
E)It represents a relationship between plant cells that photosynthesize and those that cannot.

Question 73

When pigments in an excited state relax back to ground state,they

A)release energy as fluorescence and heat.
B)lose an electron.
C)release energy as fluorescence.
D)release energy as heat.
E)absorb photons.

Question 74

Use the following information to answer the questions below.
You have learned about research conducted during the 1930s by van Niel,who studied photosynthesis in bacteria,which were observed to not release O₂ even though they fixed CO₂.
These organisms were confounding because the prevailing hypothesis at that time was that

A)autotrophs released O₂ from the splitting of CO₂ to make sugars.
B)autotrophs didn't use CO₂.
C)CO₂ was released and oxygen used up during photosynthesis.
D)only heterotrophs released O₂ while fixing carbon.
E)the process of photosynthesis was unknown at this time.

Question 75

Use the following figure to answer the questions below.

The figure above shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis.Why are they different?

A)Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
B)Bright sunlight destroys photosynthetic pigments.
C)Oxygen given off during photosynthesis interferes with the absorption of light.
D)Other pigments absorb light in addition to chlorophyll a.
E)Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis.

Question 76

Use the following figure and the compounds labelled A,B,C,D,and E to answer the following questions.

If the carbon atom of the incoming CO₂ molecule is labelled with a radioactive isotope of carbon,which organic molecules will be radioactively labelled after one cycle?

A)C only
B)B, C, D, and E
C)C, D, and E only
D)B and C only
E)B and D only

Question 77

Use the following information to answer the questions below.
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system.Plants will be grown to provide oxygen and to recycle carbon dioxide.
Since the spaceship will be too far from the sun for photosynthesis,an artificial light source will be needed.What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure?

A)full-spectrum white light
B)green light
C)a mixture of blue and red light
D)yellow light
E)UV light

Question 78

CO₂ + H₂O → [CH₂O] + O₂ represents the simplified equation for

A)chemiosmosis.
B)chemisynthesis.
C)photosynthesis.
D)photophosphorylation.
E)respiration.

Question 79

Use the following figure and the compounds labelled A,B,C,D,and E to answer the following questions.

If ATP used by this plant is labelled with radioactive phosphorus,which molecule or molecules of the Calvin cycle will be radioactively labelled first?

A)B only
B)B and C only
C)B, C, and D only
D)B and E only
E)B, C, D, and E

Question 80

Use the following information to answer the questions below.
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system.Plants will be grown to provide oxygen and to recycle carbon dioxide.
If the power fails and the lights go dark,what will happen to CO₂ levels?

A)CO₂ will rise as a result of both animal and plant respiration.
B)CO₂ will rise as a result of animal respiration only.
C)CO₂ will remain balanced because plants will continue to fix CO₂ in the dark.
D)CO₂ will fall because plants will increase CO₂ fixation.
E)CO₂ will fall because plants will cease to respire in the dark.