Chapter 8 The Green World's Gift: Photosynthesis
1) In the cycling of energy and carbon through living things, plants and some other organisms use CO2 to make carbon-containing molecules, while other organisms break down those molecules and release CO2. During this process, CO2 is produced during ________ and used during ________.
A) cellular respiration; photosynthesis
B) cellular respiration; photosynthesis and cellular respiration
C) photosynthesis; cellular respiration
D) photosynthesis; photosynthesis
E) cellular respiration; cellular respiration
Answer: A
Topic: Section 8.1
Skill: Knowledge/Comprehension
2) What product(s) do plants produce during photosynthesis that is/are used by humans and other animals?
A) glucose
B) oxygen
C) carbon dioxide
D) glucose and oxygen
Answer: D
Topic: Section 8.1
Skill: Knowledge/Comprehension
3) What product that is required by plants do animals–as well as plants–produce during cellular respiration?
A) CO2
B) glucose
C) oxygen
D) ADP
Answer: A
Topic: Section 8.1
Skill: Knowledge/Comprehension
4) Which of the following is true of plants?
A) Plants can create their own sugars using photosynthesis.
B) Plants can create their own sugars using fermentation.
C) Plants can create their own sugars using aerobic cellular respiration.
D) Plants can create their own sugars using anaerobic cellular respiration.
Answer: A
Topic: Section 8.1
Skill: Knowledge/Comprehension
5) The products of photosynthesis are:
A) O2 and sugar.
B) H2O and sugar.
C) CO2 and sugar
D) O2 and CO2
Answer: A
Topic: Section 8.1
Skill: Knowledge/Comprehension
6) The breaking apart of water in photosynthesis is critical to us as animals because photosynthesis:
A) generates ATP.
B) regenerates RuBP.
C) creates a food source.
D) consumes carbon dioxide.
E) produces oxygen.
Answer: E
Topic: Section 8.1
Skill: Knowledge/Comprehension
7) Which of the following equations properly summarizes photosynthesis?
A) C6H12O6 + 6O2 + sunlight → 6CO2 + 6H2O
B) C6H12O6 + 6CO2 + sunlight → 6O2 + 6H2O
C) 6CO2 + 6H2O + sunlight → C6H12O6 + 6O2
D) 6CO2 + 6H2O → C6H12O6 + 6O2 + sunlight
Answer: C
Topic: Section 8.1
Skill: Knowledge/Comprehension
8) The ultimate source of energy for most life on Earth is:
A) heat from the Earth.
B) the metabolic processes found in all living things.
C) the sun.
D) oxygen.
Answer: C
Topic: Section 8.1
Skill: Knowledge/Comprehension
9) What two colors of light drive most of photosynthesis?
A) red and green
B) blue and green
C) red and blue
D) green and yellow
E) red and yellow
Answer: C
Topic: Section 8.2
Skill: Knowledge/Comprehension
10) If you see a red leaf, what color(s) of light in the visible light spectrum is/are being reflected?
A) red
B) all colors except red
C) all colors
D) no colors
Answer: A
Topic: Section 8.2
Skill: Application/Analysis
11) Photosynthesis is driven by the ________ light spectrum.
A) visible
B) infrared
C) ultraviolet
D) microwave
Answer: A
Topic: Section 8.2
Skill: Knowledge/Comprehension
12) Which of the following statements is true?
A) The shortest wavelength of light is the ultraviolet ray, which is the highest in energy.
B) The longest wavelength of light is the ultraviolet ray, which is the highest in energy.
C) The shortest wavelength of light is the visible light, which is the highest in energy.
D) The shortest wavelength of light is the infrared ray, which is the highest in energy.
E) The longest wavelength of light is the infrared ray, which is the highest in energy.
Answer: A
Topic: Section 8.2
Skill: Knowledge/Comprehension
13) ________ permit CO2 to enter the leaf and O2 to escape.
A) Mesophyll cells
B) Thylakoids
C) Stomata
D) Chloroplasts
Answer: C
Topic: Section 8.2
Skill: Knowledge/Comprehension
14) The stomata are located in the leaf's ________, and the chloroplasts are located in the leaf's ________.
A) epidermis; epidermis
B) mesophyll; epidermis
C) epidermis; mesophyll
D) epidermis; stomata
E) mesophyll; mesophyll
Answer: C
Topic: Section 8.2
Skill: Knowledge/Comprehension
15) Chlorophyll is found in which part of the plant cell?
A) stroma
B) cytoplasm
C) thylakoid
D) plasma membrane
Answer: C
Topic: Section 8.2
Skill: Knowledge/Comprehension
16) The site of photosynthesis in a cell is the:
A) mitochondrion.
B) central vacuole.
C) stomata.
D) chloroplast.
Answer: D
Topic: Section 8.2
Skill: Knowledge/Comprehension
17) What function does sunlight perform in photosynthesis?
A) Sunlight excites electrons in chlorophyll to a higher energy level.
B) Sunlight fixes the CO2 into glucose.
C) Sunlight converts electrons in chlorophyll to a lower energy state.
D) Sunlight converts electrons in water to a lower energy state.
E) Sunlight excites electrons in water to a higher energy level.
Answer: A
Topic: Section 8.2
Skill: Knowledge/Comprehension
18) The purpose of chlorophyll is to:
A) absorb light.
B) let CO2 enter the plant.
C) make ATP.
D) make NADPH.
Answer: A
Topic: Section 8.2
Skill: Knowledge/Comprehension
19) Chlorophyll a and the accessory pigments of a photosystem act as an antenna by:
A) being the primary electron acceptor.
B) absorbing energy from sunlight and passing it on.
C) absorbing CO2 and passing it on.
D) absorbing energy from NADPH and passing it on.
Answer: B
Topic: Section 8.2
Skill: Knowledge/Comprehension
20) The transfer of electrons from chlorophyll a molecules to the primary electron acceptor is an example of a/an:
A) redox reaction.
B) synthesis reaction.
C) light reaction.
D) absorption reaction.
Answer: A
Topic: Section 8.2
Skill: Knowledge/Comprehension
21) The light reactions occur in the:
A) mitochondrial membrane.
B) thylakoid membrane.
C) stoma.
D) thylakoid compartment.
E) mitochondrial compartment.
Answer: B
Topic: Section 8.3
Skill: Knowledge/Comprehension
22) Which of the following statements about photosynthesis is false?
A) Sunlight excites electrons from chlorophyll, which are captured by ATP.
B) In the light reactions, electrons eventually wind up on NADPH.
C) Photosynthesis involves many redox reactions similar to the electron transport chain used during cellular respiration.
D) During the light reactions, ATP and NADPH are synthesized.
E) A waste product of the light reactions is O2.
Answer: A
Topic: Section 8.3
Skill: Knowledge/Comprehension
23) What is the primary purpose of the light reactions of photosynthesis?
A) to produce glucose
B) to create oxygen gas
C) to release electrons needed to convert solar energy to chemical energy
D) to remove carbon dioxide gas from the atmosphere
Answer: C
Topic: Section 8.3
Skill: Knowledge/Comprehension
24) The absorption of light energy by a photosystem:
A) transfers an electron from a reaction center to accessory pigment molecules.
B) causes electrons to be transferred from NADP+ to a reaction center.
C) boosts electrons to a higher energy level.
D) causes electrons to lose energy until they reach the reaction center.
Answer: C
Topic: Section 8.3
Skill: Knowledge/Comprehension
25) Both photosynthesis and cellular respiration rely on electron carrier molecules to provide electrons to ultimately help produce ATP. In photosynthesis, the source of electrons is ________ and in cellular respiration the source of electrons is ________.
A) carbon dioxide; oxygen
B) glucose; oxygen
C) oxygen; carbon dioxide
D) water; glucose
Answer: D
Topic: Section 8.3
Skill: Application/Analysis
26) The oxygen produced during photosynthesis comes from:
A) water.
B) carbohydrates.
C) carbon dioxide.
D) the air plants take in.
Answer: A
Topic: Section 8.3
Skill: Knowledge/Comprehension
27) The splitting of water in photosynthesis provides:
A) CO2 and electrons.
B) O2 and electrons.
C) glucose and electrons.
D) hydrogen ions and light energy.
Answer: B
Topic: Section 8.3
Skill: Knowledge/Comprehension
28) Chloroplasts transform ________ energy into the ________ energy of ATP.
A) heat; light
B) light; heat
C) heat; chemical
D) light; chemical
E) chemical; heat
Answer: D
Topic: Section 8.3
Skill: Application/Analysis
29) During the light reactions of photosynthesis, which of these does not occur?
A) Water is used to regenerate the electrons in the chlorophyll that were excited by sunlight.
B) Sunlight excites electrons in chlorophyll, which are transferred directly to ATP.
C) Sunlight excites electrons in chlorophyll, allowing an electron acceptor up the energy hill to accept them.
D) Sunlight excites electrons in chlorophyll, which eventually wind up on NADPH.
Answer: B
Topic: Section 8.3
Skill: Application/Analysis
30) The products of the light reactions that are then used by the Calvin cycle are:
A) ATP and NADPH.
B) ADP and NADP+.
C) ATP and O2.
D) O2 and NADPH.
E) ATP and CO2.
Answer: A
Topic: Section 8.3
Skill: Knowledge/Comprehension
31) The electrons excited by sunlight in photosystem I are replaced by ________, and the electrons excited by sunlight in photosystem II are replaced by ________.
A) electrons from water; electrons from photosystem I
B) electrons from water; electrons from carbon dioxide
C) electrons from water; electrons from water
D) electrons from carbon dioxide; electrons from water
E) electrons from photosystem II; electrons from water
Answer: E
Topic: Section 8.3
Skill: Knowledge/Comprehension
32) Electrons from photosystem I are transferred down an electron transport chain to ________, which become reduced to ________.
A) NAD+; NADPH
B) NADPH; NADP+
C) NADP+; NADPH
D) ADP; ATP
Answer: C
Topic: Section 8.3
Skill: Knowledge/Comprehension
33) As a by-product of photosynthesis, what percentage of the Earth's atmosphere is oxygen?
A) 31 percent
B) 41 percent
C) 21 percent
D) 10 percent
E) 50 percent
Answer: C
Topic: Section 8.3
Skill: Knowledge/Comprehension
34) During the light reactions of photosynthesis:
A) H2O is oxidized to oxygen and hydrogen ions.
B) ATP is used to produce H2O.
C) ATP is used to produce NADPH.
D) CO2 is fixed into glucose.
Answer: A
Topic: Section 8.3
Skill: Application/Analysis
35) Plants make ATP during the light reactions of photosynthesis. Why do plants also need to carry out the process of cellular respiration?
A) The ATP made during photosynthesis is different from the ATP made during cellular respiration.
B) The ATP made during photosynthesis is only enough to fuel the dark reactions. The plant has to carry out cellular respiration to make ATP for other metabolic activities.
C) Plants need to make ATP from cellular respiration only when the conditions for photosynthesis are bad.
D) Plants do not need to perform cellular respiration.
Answer: B
Topic: Section 8.3
Skill: Application/Analysis
36) Where does the NADPH created during the light reactions accumulate?
A) in the stomata
B) in the thylakoid membrane
C) in the leaf's epidermis
D) in the thylakoid compartment
E) in the stroma
Answer: E
Topic: Section 8.3
Skill: Knowledge/Comprehension
37) During photosynthesis, energy is released and used to create ATP when:
A) electrons are passed down the energy hill during the light reactions.
B) electrons jump from a reaction center to a primary electron acceptor.
C) CO2 is fixed into sugars in the light reactions.
D) water is split, releasing oxygen.
E) electrons are passed from photosystem I to NADPH.
Answer: A
Topic: Section 8.3
Skill: Knowledge/Comprehension
38) The electron carrier in photosynthesis that will donate electrons to CO2 so that it can be fixed into sugars is:
A) NADPH.
B) glucose.
C) NADH.
D) FADH.
E) CO2.
Answer: A
Topic: Section 8.4
Skill: Knowledge/Comprehension
39) The Calvin cycle takes place in the:
A) thylakoids.
B) grana.
C) stroma.
D) cytoplasm.
Answer: C
Topic: Section 8.4
Skill: Knowledge/Comprehension
40) The Calvin cycle requires all of the following except:
A) O2.
B) ATP.
C) NADPH.
D) RuBP.
Answer: A
Topic: Section 8.4
Skill: Knowledge/Comprehension
41) Carbon fixation is taking place when plants:
A) oxidize CO2.
B) incorporate CO2 into sugars.
C) ingest CO2.
D) produce CO2.
E) convert CO2 into ATP.
Answer: B
Topic: Section 8.4
Skill: Knowledge/Comprehension
42) For every six carbon dioxide molecules fixed by the Calvin cycle, how many molecules of G3P exit the cycle?
A) one
B) two
C) three
D) six
Answer: B
Topic: Section 8.4
Skill: Application/Analysis
43) How many carbon dioxide molecules are required to make one molecule of glucose?
A) two
B) three
C) six
D) eight
Answer: C
Topic: Section 8.4
Skill: Application/Analysis
44) The sugar that first bonds with carbon dioxide in the Calvin cycle is:
A) 3-PGA.
B) G3P.
C) RuBP.
D) rubisco.
Answer: C
Topic: Section 8.4
Skill: Knowledge/Comprehension
45) Sugars are created during:
A) aerobic respiration.
B) the Calvin cycle of photosynthesis.
C) the light reactions of photosynthesis.
D) anaerobic respiration.
Answer: B
Topic: Section 8.4
Skill: Knowledge/Comprehension
46) During the Calvin cycle, plants:
A) fix CO2 into sugar.
B) create ATP.
C) oxidize H2O to oxygen.
D) convert solar energy to chemical energy.
Answer: A
Topic: Section 8.4
Skill: Knowledge/Comprehension
47) Photorespiration is when:
A) plants use sugars by respiration.
B) plants produce sugars during photosynthesis.
C) the enzyme rubisco binds O2 during the Calvin cycle.
D) the enzyme rubisco binds CO2 during the Calvin cycle.
Answer: C
Topic: Section 8.5
Skill: Knowledge/Comprehension
48) Photorespiration results in:
A) no change in the sugar being produced during photosynthesis.
B) more sugar being produced during photosynthesis.
C) less sugar being produced during photosynthesis.
D) sometimes more and sometimes less sugar being produced during photosynthesis.
Answer: C
Topic: Section 8.5
Skill: Knowledge/Comprehension
49) Photorespiration occurs most on:
A) hot, dry days.
B) hot, humid days.
C) cool, cloudy days.
D) cold, dry days.
E) cloudy, rainy days.
Answer: A
Topic: Section 8.5
Skill: Knowledge/Comprehension
50) During photorespiration, rubisco binds with ________ , and during photosynthesis, rubisco binds with ________.
A) oxygen; a six-carbon sugar
B) oxygen; a five-carbon sugar
C) CO2; oxygen
D) a five-carbon sugar; oxygen
E) oxygen; CO2 and a five-carbon sugar
Answer: E
Topic: Section 8.5
Skill: Knowledge/Comprehension
51) A C4 plant is different from a C3 plant because a C4 plant:
A) can leave its stomata open longer without ill effect.
B) stores CO2 in four-carbon molecules before the CO2 enters the Calvin cycle.
C) does not have bundle-sheath cells.
D) performs photorespiration.
Answer: B
Topic: Section 8.5
Skill: Knowledge/Comprehension
52) What advantage is it for some plants to use C4 and CAM photosynthesis?
A) They can conserve water and reduce photorespiration under hot, dry conditions
B) They can conserve water and produce four-carbon sugars instead of glucose
C) They can absorb carbon dioxide more efficiently when atmospheric CO2 levels are low.
D) They can use the Calvin cycle at night when conditions are cooler and more humid.
Answer: A
Topic: Section 8.6
Skill: Application/Analysis
53) Which of the following types of plants would most likely be found in the Mojave Desert?
A) CAM
B) C3
C) C4
D) CAM, C3, and C4 would all be equally likely in this environment.
Answer: A
Topic: Section 8.6
Skill: Knowledge/Comprehension
54) Which of the following is a C4 plant?
A) cactus
B) lilac
C) corn
D) pine trees
E) orchids
Answer: C
Topic: Section 8.6
Skill: Knowledge/Comprehension
55) Which of the following is a CAM plant?
A) lilac
B) cactus
C) sugarcane
D) pine tree
E) corn
Answer: B
Topic: Section 8.6
Skill: Knowledge/Comprehension
56) Which type of photosynthesis do most plants use?
A) C4
B) C3
C) CAM
D) photorespiration
Answer: B
Topic: Section 8.6
Skill: Knowledge/Comprehension
57) Only plants can carry out photosynthesis.
Answer: FALSE
Topic: Section 8.1
Skill: Knowledge/Comprehension
58) Oxygen is required to carry out photosynthesis.
Answer: FALSE
Topic: Section 8.1
Skill: Knowledge/Comprehension
59) Plants perform only photosynthesis, not cellular respiration.
Answer: FALSE
Topic: Section 8.1
Skill: Application/Analysis
60) Most plant leaves appear green because they absorb green light.
Answer: FALSE
Topic: Section 8.2
Skill: Knowledge/Comprehension
61) Photosynthesis forms ATP using oxidation-reduction reactions similar to those seen in the electron transport chain of respiration.
Answer: TRUE
Topic: Section 8.2
Skill: Application/Analysis
62) If something is oxidized, it loses electrons.
Answer: TRUE
Topic: Section 8.2
Skill: Knowledge/Comprehension
Match the following.
A) mesophyll
B) grana
C) stomata
D) stroma
E) thylakoids
63) The leaf tissue where most photosynthesis occurs
Topic: Section 8.2
Skill: Knowledge/Comprehension
64) The light reactions occur here
Topic: Section 8.2
Skill: Knowledge/Comprehension
65) Stacks of membrane inside the chloroplast
Topic: Section 8.2
Skill: Knowledge/Comprehension
66) The Calvin cycle takes place in this space
Topic: Section 8.2
Skill: Knowledge/Comprehension
67) These allow carbon dioxide to enter the leaf and oxygen to exit
Topic: Section 8.2
Skill: Knowledge/Comprehension
Answers: 63) A 64) E 65) B 66) D 67) C
68) Photosynthetic organisms provide two products that animals could not live without: ________ and ________.
Answer: organic molecules; oxygen
Topic: Section 8.1
Skill: Knowledge/Comprehension
69) The two colors of light that drive most photosynthesis are ________ and ________.
Answer: red; blue
Topic: Section 8.2
Skill: Knowledge/Comprehension
70) When sunlight hits chlorophyll, the electrons are excited out of the chlorophyll; the electrons go ________ an energy hill, and as they pass through the electron transport chain they go ________ an energy hill.
Answer: up; down
Topic: Section 8.3
Skill: Knowledge/Comprehension
71) During the process of ________, carbon dioxide is incorporated into an organic molecule.
Answer: fixation
Topic: Section 8.4
Skill: Knowledge/Comprehension
72) The enzyme ________ can bind both carbon dioxide and oxygen.
Answer: rubisco
Topic: Section 8.5
Skill: Knowledge/Comprehension
73) Plants and animals are mutually dependent on each other. Explain the energy-producing metabolic processes used by plants and animals, and name the products that result. Describe how animals benefit from the products of plant metabolism and how plants benefit from the products of animal metabolism.
Answer: Plants produce sugars and oxygen during photosynthesis, using carbon dioxide and water in the process. Animals produce carbon dioxide and water during cellular respiration, using sugars and oxygen in the process. Animals provide plants with carbon dioxide, and plants provide animals with sugars and oxygen.
Topic: Section 8.1
Skill: Application/Analysis
74) Describe how cellular respiration and photosynthesis are different.
Answer: In respiration, sugars are oxidized to CO2 to gain energy using oxygen as the final electron acceptor, forming water. In photosynthesis, water is split to produce oxygen, and the electrons provide energy to fix CO2 into sugars.
Topic: Section 8.1
Skill: Application/Analysis
75) Your friend Bill says that all food on Earth ultimately comes from photosynthesis. Your friend Tom disagrees, saying that, "Cows and pigs don't photosynthesize, and they are food." Who do you think is correct, and why?
Answer: Bill is correct. Without photosynthesis, cows and pigs would have nothing to eat and would starve; therefore, they also depend on photosynthesis.
Topic: Section 8.1
Skill: Application/Analysis
76) Your friend lives in a basement apartment with no windows. She loves plants, but every time she tries to grow one it dies. What might you suggest your friend try, and why?
Answer: Your friend should keep her plants under a light source at least 12 hours a day. Plants need the sunlight to produce ATP and NADPH needed to make sugars. With no light, no photosynthesis occurs, and the plant can't grow.
Topic: Section 8.2
Skill: Application/Analysis
77) Unlike animals, plants are able to obtain ATP through two processes. What are the two processes? Now consider deciduous trees, which drop their leaves in the fall. Do deciduous trees continue to use both these processes during the winter? If not, how do they stay alive during the winter until they grow new leaves in the spring?
Answer: Plants obtain ATP through cellular respiration as well as photosynthesis. Deciduous trees are unable to conduct photosynthesis after they lose their leaves in the fall. However, deciduous trees can continue to obtain ATP through cellular respiration. This provides the ATP they need for cellular processes during the winter. When the trees grow new leaves in the spring, they can resume photosynthesis.
Topic: Section 8.2
Skill: Application/Analysis
78) You perform an experiment using an aquatic plant called elodea to determine which color of light is most effective at driving photosynthesis. You take three plants, immersed under water, and place plant A under blue light, plant B under red light, and plant C under green light. You notice bubbles coming off the leaves. More bubbles are coming from plants A and B, and few are coming from plant C. What is producing the bubbles? How do these results determine which color of light is most effective at driving photosynthesis?
Answer: The bubbles are oxygen being produced by the splitting of water during the light reactions. Red and blue light are absorbed, so they are more effective at driving photosynthesis, thus producing more oxygen. Green light is not absorbed, so it is not as effective at driving photosynthesis, thus producing less oxygen.
Topic: Section 8.3
Skill: Application/Analysis
79) It has been argued that, wherever in the universe we might find living things, we will find some of them to be colored. Do you agree? Explain.
Answer: This is probably true considering that most life as we know it ultimately depends on photosynthesis, and photosynthesis depends on colored pigments. So life on other planets will probably include organisms colored by pigments that absorb light energy.
Topic: Section 8.2
Skill: Synthesis/Evaluation
80) Up until the 1930s it was assumed that the carbohydrates plants produced resulted from the combination of carbon atoms with water, and the oxygen released came from the splitting of the carbon dioxide molecule. You are a scientist testing this hypothesis. You have available to you water labeled with radioactive oxygen atoms and carbon di