Photosynthesis - Biology

(7.1) Which of these types of organisms produces the biosphere's food supply?
A. photoheterotrophs
B. chemoautotrophs
C. chemoheterotrophs
D. photoautotrophs

D. photoautotrophs

\#(7.2) Carbon dioxide enters a leaf through the \_____.
A. mesophyll
B. thylakoids
C. chloroplasts
D. stomata

D. stomata

\#(7.2) Chlorophyll molecules are found in which part of the chloroplast?
A. stroma
B. plasma membrane
C. stomata
D. grana

grana

\#(7.2) In rosebushes, chlorophyll is responsible for the process of photosynthesis. Chlorophyll is located in \_____.
A. mesophyll cells, which are in thylakoids in the chloroplasts of a leaf
B. thylakoids, which are in chloroplasts in the mesophyll cells of a leaf
C. chloroplasts, which are in mesophyll cells in the thylakoids of a leaf
D. thylakoids, which are in mesophyll cells in the chloroplasts of a leaf

B. thylakoids, which are in chloroplasts in the mesophyll cells of a leaf

\#(7.2) You could distinguish a granum from an inner mitochondrial membrane because the granum, but not the inner mitochondrial membrane, would \_____.
A. have photosynthetic pigments
B. function in energy transformation
C. be inside a mitochondrion
D. contain protein but not lipids

A. have photosynthetic pigments

\#(7.3) In an experiment, a plant was given \_____ containing radioactive 18O, and the radioactive oxygen atoms were used to make sugar.
A. chlorophyll
B. water
C. carbon dioxide
D. oxygen gas

C. carbon dioxide

\#(7.3) In photosynthesis, the oxygen atoms from carbon dioxide end up \_____.
A. in sugar molecules and in water
B. in sugar molecules and carbon dioxide
C. as molecular oxygen and water
D. as molecular oxygen and in sugar molecules

A. in sugar molecules and in water

\#(7.3) The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. Follow the equation below and determine where oxygen comes from.
A. light
B. water
C. glucose
D. carbon dioxide

B. water

\#(7.4) Cellular respiration and photosynthesis are similar in that both involve \_____.
A. the production of sugars
B. water splitting
C. the release of O2 into the atmosphere
D. oxidation-reduction (redox) reactions

D. oxidation-reduction (redox) reactions

\#(7.5) The "photo-" part of the word photosynthesis refers to the \_____, whereas "-synthesis" refers to \_____.
A. Calvin cycle ... the reactions in the stroma
B. Calvin cycle ... carbon fixation
C. reactions in the stomata ... the reactions in the thylakoids
D. light reactions that occur in the thylakoids ... carbon fixation

D. light reactions that occur in the thylakoids ... carbon fixation

\#(7.5) The photosynthetic event known as the Calvin cycle occurs in the \_____.
A. thylakoid compartment
B. thylakoid membrane
C. stomata
D. stroma

D. stroma

\#(7.6) Considering the wavelengths of light shown below, the pigments in the granum absorb mainly in which range?
A. green, which is why plants are green
B. the infrared
C. the entire spectrum of white light
D. blue-violet and red-orange

D. blue-violet and red-orange

\#(7.6) The most important role of pigments in photosynthesis is to \_____.
A. release energy from glucose molecules
B. store energy in glucose molecules
C. capture light energy
D. screen out harmful ultraviolet rays

C. capture light energy

\#(7.6) Which of the following colors is most strongly reflected by chlorophyll?
A. red
B. yellow
C. orange
D. green

D. green

\#(7.7) The reaction center, antenna molecules, and primary electron acceptors that cluster in the thylakoid membrane form which structure?
A. electron transport chain
B. photosystem
C. fluorescence center
D. carbon-fixation unit

B. photosystem

\#(7.7) The synthesis of glucose by photosynthesis is an endergonic process. The source of the energy for the excited electrons is \_____.
A. water
B. light
C. carbon dioxide
D. chlorophyll

B. light

\#(7.7) When chloroplast pigments absorb light, \_____.
A. their electrons become excited
B. they lose potential energy
C. the Calvin cycle is triggered
D. they become reduced

A. their electrons become excited

\#(7.8) As photosynthesis occurs in chloroplasts, O2 is produced from \_____ via a series of reactions associated with \_____.
A. CO2 ... photosystem II
B. H2O ... photosystem I
C. H2O ... photosystem II
D. CO2 ... Calvin cycle

C. H2O ... photosystem II

\#(7.8) During photosynthesis, an electron transport chain is used to \_____.
A. transport electrons from photosystem II to photosystem I
B. transport excited electrons from P680 to an electron acceptor
C. transport excited electrons from P700 to an electron acceptor
D. transport NADPH from the light reactions to the Calvin cycle

A. transport electrons from photosystem II to photosystem I

\#(7.8) Molecular oxygen is produced during \_____.
A. aerobic respiration
B. light reactions of photosynthesis
C. glycolysis
D. the Calvin cycle

B. light reactions of photosynthesis

\#(7.8) The light reactions of photosynthesis generate high-energy electrons, which end up in \_____. The light reactions also produce \_____ and \_____.
A. chlorophyll ... ATP ... NADPH
B. NADPH ... ATP ... oxygen
C. ATP ... NADPH ... oxygen
D. oxygen ... sugar ... ATP

B. NADPH ... ATP ... oxygen

\#(7.8) Where do the electrons needed by photosystem II originate?
A. ATP
B. the electron transport chain
C. water
D. other chlorophyll molecules

C. water

\#(7.9) Both mitochondria and chloroplasts \_____.
A. release oxygen as a by-product
B. obtain electrons from water
C. reduce NAD+, forming NADP
D. use an H+ gradient to produce ATP

D. use an H+ gradient to produce ATP

\#(7.9) In addition to its function in mitochondria, the chemiosmotic mechanism is important for generating ATP during the \_____.
A. synaptic transmission
B. process of intracellular digestion within lysosomes
C. photoexcitation of electrons
D. fermentation of glucose

C. photoexcitation of electrons

\#(7.9) Light reactions are located in the thylakoid membrane because \_____.
A. the membrane brings chlorophyll closer to the light
B. the enzymes involved require a lipid bound to their active site
C. the membrane functions as a mitochondrial membrane but at night
D. chemiosmosis can occur across the thylakoid membrane

D. chemiosmosis can occur across the thylakoid membrane

\#(7.9) The energy used to produce ATP in the light reactions of photosynthesis comes from \_____.
A. movement of H+ through a membrane
B. splitting water
C. carbon fixation
D. the burning of sugar molecules

A. movement of H+ through a membrane

\#(7.10) Although the reactions of the Calvin cycle are not directly dependent on light, they usually do not occur at night. Why?
A. It is often too cold at night for these reactions to take place.
B. The Calvin cycle depends on products of the light reactions.
C. Carbon dioxide concentrations decrease at night.
D. Plants usually open their stomata at night.

B. The Calvin cycle depends on products of the light reactions.

\#(7.10) In the Calvin cycle carbon dioxide provides \_____, whereas ATP and NADPH provide \_____ and \_____, respectively.
A. hydrogen ... carbon ... energy
B. carbon ... energy ... high-energy electrons
C. high-energy electrons ... energy ... carbon
D. energy ... carbon ... high-energy electrons

B. carbon ... energy ... high-energy electrons

\#(7.10) NADP+ is required for photosynthesis because it \_____.
A. forms part of photosystem II
B. forms NADPH to be used in the Calvin cycle
C. helps produce ATP from the light reactions
D. absorbs light energy

B. forms NADPH to be used in the Calvin cycle

\#(7.10) Rubisco is the \_____.
A. enzyme in C3 plants that first captures CO2 to begin the Calvin cycle
B. first stable intermediate in CAM metabolism
C. enzyme that forms a four-carbon compound in CAM metabolism
D. enzyme responsible for splitting H2O to produce O2 in photosynthesis

A. enzyme in C3 plants that first captures CO2 to begin the Calvin cycle

\#(7.10) The Calvin cycle is a series of reactions that \_____.
A. produce oxygen gas
B. convert light energy to chemical energy
C. produce NADPH and ATP
D. assemble sugar molecules by fixing carbon

D. assemble sugar molecules by fixing carbon

\#(7.10) The final output of the Calvin cycle is \_____.
A. 3-PGA
B. G3P
C. RuBP
D. ATP

B. G3P

\#(7.10) What is the role of NADP+ in photosynthesis?
A. It is part of the electron transport chain and is involved with the manufacture of ATP.
B. It is reduced and then carries electrons to the Calvin cycle.
C. It assists chlorophyll in capturing light.
D. It acts as the primary electron acceptor for the photosystems.

B. It is reduced and then carries electrons to the Calvin cycle.

\#(7.11 and 7.12) A red chemical dye known as phenol red changes to yellow when CO2 is present. A small green plant seedling is placed in phenol red and then placed in the dark. Which of the following is most likely to occur?
A. The solution is red to begin with, and it will turn yellow because photosynthesis is occurring.
B. The solution is yellow to begin with, and it will turn red because respiration is occurring.
C. The solution is yellow to begin with, and it will turn red because photosynthesis is occurring.
D. The solution is red to begin with, and it will turn yellow because respiration is occurring.

D. The solution is red to begin with, and it will turn yellow because respiration is occurring.

\#(7.11) C4 and CAM plants have adapted to living in environments where water loss is a problem. C4 plants fix carbon dioxide \_____, whereas CAM plants fix carbon at \_____.
A. at different times of the day ... different seasons
B. at different times of the day ... different locations within the leaf
C. in different locations ... different times of the day
D. during different seasons ... different locations

C. in different locations ... different times of the day

\#(7.11) C4 plants fix carbon dioxide in the \_____.
A. stroma
B. bundle-sheath cells
C. matrix
D. mesophyll

B. bundle-sheath cells

\#(7.11) C4 plants have evolved different photosynthetic mechanisms. These plants \_____.
A. conserve water more efficiently by shutting their stomata during the day
B. are adapted to living in cold, wet climates where there is no water shortage
C. fix CO2 into a four-carbon compound instead of a three-carbon compound
D. do not fix CO2 through the Calvin cycle

C. fix CO2 into a four-carbon compound instead of a three-carbon compound

\#(7.12) You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark?
A. While it did have access to light before you left, the plant stored energy in the form of sugars or starch, and it was able to derive energy from those during your vacation.
B. Even though the plant received no visible light, it was able to use the shortwave part of the electromagnetic spectrum (gamma rays and X-rays) to carry out photosynthesis.
C. Even though it cannot carry out the light reactions, the plant can still produce sugars because the Calvin cycle does not require light.
D. When light energy is not available, plants can derive energy from inorganic molecules.

A. While it did have access to light before you left, the plant stored energy in the form of sugars or starch, and it was able to derive energy from those during your vacation.

\#(7.13) Solar radiation warms the surface of the planet and then is radiated back in the form of \_____.
A. UV radiation
B. CO2
C. ozone
D. infrared light

D. infrared light

\#(7.13) Which of the following is a synthetic greenhouse gas?
A. chlorofluorocarbon
B. ozone
C. carbon dioxide
D. methane

A. chlorofluorocarbon

\#(7.14) Which of the following may happen as a result of ozone depletion?
A. a change in the planet's climate
B. a gradual rise in sea levels
C. a shift in the location of deserts such as the Sahara
D. an increase in the number of individuals with skin cancer

D. an increase in the number of individuals with skin cancer\#