Deck 7: Photosynthesis: Using Light to Make Food

Question 1

________ cells in leaves are specialized for photosynthesis.

A)Companion
B)Mesophyll
C)Sclerenchyma
D)Tracheid

Answer 1

B

Question 2

Which of the following is an example of a photoautotroph?

A)algae in freshwater and marine ecosystems
B)grizzly bears in Alaska
C)bacteria in our mouth
D)mushrooms growing on the side of a dead tree

Answer 2

A

Question 3

What is the name given to organisms that can make their own food and thus sustain themselves without consuming organic molecules derived from other organisms?

A)chemotrophs
B)heterotrophs
C)synthesizers
D)autotrophs

Answer 3

D

Question 4

CO₂ enters and O₂ escapes from a leaf via

A)stomata.
B)thylakoids.
C)grana.
D)stroma.

Question 5

What is the source of energy that provides the boost for electrons during photosynthesis?

A)light
B)NADPH
C)cellular respiration
D)ATP

Question 6

What is the likely origin of chloroplasts?

A)mitochondria that had a mutation for photosynthesis
B)photosynthetic prokaryotes that lived inside eukaryotic cells
C)prokaryotes with photosynthetic mitochondria
D)eukaryotes that engulfed photosynthetic fungi

Question 7

If you expose a photosynthesizing plant to water that contains both radioactive H and radioactive O, in which of the products of photosynthesis will the radioactive H and O show up?

A)H and O both in glucose
B)H in glucose; O in water
C)H in water; O in glucose
D)H in glucose and water; O in O₂

Question 8

Which of the following molecules is a reactant of photosynthesis?

A)CO₂
B)glucose
C)O₂
D)chlorophyll

Question 9

Which of the following statements concerning the role of redox reactions in photosynthesis and cellular respiration is true?

A)Photosynthesis involves only reductions, whereas respiration involves only oxidations.
B)Photosynthesis involves only oxidations, whereas respiration involves only reductions.
C)In photosynthesis, carbon dioxide is oxidized to form sugar, whereas in respiration, sugar is reduced to form carbon dioxide.
D)In photosynthesis, carbon dioxide is reduced to form sugar, whereas in respiration, sugar is oxidized to form carbon dioxide.

Question 10

Which of the following statements comparing photosynthesis and cellular respiration is false?

A)ATP is not produced during photosynthesis; it is produced only during cellular respiration.
B)Photosynthesis is ultimately powered by light energy and respiration by the chemical energy of fuel molecules.
C)Photosynthesis consumes CO₂; respiration consumes O₂.
D)Photosynthesis produces O₂; respiration produces CO₂.

Question 11

Photoautotrophs

A)make sugar by using organic raw materials.
B)produce organic molecules from inorganic molecules.
C)eat other organisms that use light energy to make food molecules.
D)include only the green plants.

Question 12

Which of the following are produced during the light reactions of photosynthesis?

A)glucose, ADP, NADP⁺
B)glucose, ADP, NADP⁺, CO₂
C)ADP, NADP⁺, O₂
D)ATP, NADPH, O₂

Question 13

The oxygen released into the air as a product of photosynthesis comes from

A)water.
B)glucose.
C)carbon dioxide.
D)chlorophyll.

Question 14

A redox reaction involves the transfer of

A)oxygen.
B)water.
C)an electron.
D)carbon dioxide.

Question 15

In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called the

A)stomata.
B)thylakoid.
C)matrix.
D)stroma.

Question 16

In most green plants, chloroplasts are

A)concentrated in a zone of leaf tissue called the mesophyll.
B)concentrated in a portion of the leaf called the stroma.
C)evenly distributed throughout the leaf tissue.
D)evenly distributed throughout the entire plant.

Question 17

Thylakoids are arranged in stacks called

A)cristae.
B)stomata.
C)grana.
D)vacuoles.

Question 18

Where is chlorophyll found in a plant cell?

A)stroma
B)thylakoid membranes
C)cytoplasm
D)cristae

Question 19

The light reactions occur in the ________, while the Calvin cycle occurs in the ________.

A)stroma; thylakoid membranes
B)stroma; nucleus
C)cytoplasm; thylakoid membrane
D)thylakoid membranes; stroma

Question 20

Autotrophs that utilize light as their energy source are

A)chemosynthetic autotrophs.
B)photoautotrophs.
C)fungi.
D)heterotrophs.

Question 21

Which of the following wavelengths of light would you expect to be reflected or transmitted by chlorophyll a?

A)blue
B)green
C)yellow
D)red

Question 22

Which of the following statements about the absorption of photons by pigment molecules is true?

A)It takes several minutes for the pigment electrons to become excited.
B)Photons raise electrons in pigments to the ground state.
C)Excitation of the electrons is a very stable state.
D)Energy can be released by the excited electron as heat, light, or fluorescence.

Question 23

Which of the following is a normal process of photosynthesis that could not occur if all reaction centers were inactivated by a toxin?

A)donation of excited electrons by chlorophyll a to a primary electron acceptor
B)donation of excited electrons by chlorophyll b to a primary electron acceptor
C)absorption of photons by chlorophyll b
D)absorption of photons by carotenoids

Question 24

Which of the following molecules is a product of photosynthesis?

A)CO₂ and chlorophyll
B)glucose and O₂
C)O₂ and CO₂
D)glucose and CO₂

Question 25

Clusters of light-gathering pigments in a photosystem

A)pass energy to the reaction center.
B)are found in the roots of plants.
C)absorb electrons.
D)break down H₂O.

Question 26

The energy that excites the photosystems is supplied by

A)electrons passing down the electron transport chain.
B)ATP.
C)photons.
D)NADPH.

Question 27

The electron transport chains of the light reactions

A)are located in the stroma.
B)shuttle electrons from photosystem II to photosystem I.
C)provide energy for the citric acid cycle.
D)are found on the plasma membrane of mesophyll cells.

Question 28

In a photosystem, clusters of chlorophyll a, chlorophyll b, and carotenoid pigments function most like

A)an antenna.
B)a propeller on a motorboat.
C)a windmill.
D)a spring.

Question 29

Which of the following is part of the light reaction?

A)carbon fixation
B)reduction of carbon
C)regeneration of NADP⁺
D)formation of waste products in the form of O₂

Question 30

Plant cells are protected from the harmful effects of excessive light energy and reactive oxidative molecules by

A)mitochondria.
B)chlorophyll.
C)carotenoids.
D)ATP.

Question 31

Why are most plants green?

A)Chlorophyll a reflects green light.
B)Chlorophyll a absorbs green light.
C)Chlorophyll b primarily uses green light as the source of energy for photosynthesis.
D)Green helps plants blend into their environment as a sort of camouflage.

Question 32

Which of the following colors contributes the least energy to photosynthesis?

A)blue
B)red
C)orange
D)green

Question 33

A packet of light energy is called a

A)quantum.
B)pigment.
C)photon.
D)phaser.

Question 34

The full range of electromagnetic energy is called the ________ spectrum.

A)visible
B)electromagnetic
C)energy
D)ultraviolet

Question 35

Which of the following are produced during the Calvin cycle?

A)glucose, ADP, NADP⁺
B)glucose, ADP, NADP⁺, CO₂
C)ATP, NADPH, O₂
D)ATP, NADPH, CO₂

Question 36

Which of the following photosynthetic pigments can be found at the photosystem reaction center?

A)chlorophyll b
B)chlorophyll a
C)a carotenoid
D)phycocyanin

Question 37

Carbon fixation

A)occurs when carbon atoms from CO₂ are incorporated into an organic molecule.
B)supplies the cell with ATP.
C)occurs during the light reactions.
D)provides the cell with a supply of NADPH molecules.

Question 38

As a result of the cascade of electrons down the electron transport chains of the light reactions,

A)NADPH is reduced to NADP⁺.
B)NADPH is oxidized to NADP⁺.
C)NADP⁺ is reduced to NADPH.
D)NADP⁺ is oxidized to NADPH.

Question 39

Chlorophyll b

A)is best at absorbing the energy of green light.
B)is best at absorbing the energy of blue-violet and red light, just like chlorophyll a.
C)passes absorbed energy to chlorophyll a.
D)catalyzes the incorporation of carbon atoms into RuBP.

Question 40

Sunlight is a type of ________ energy.

A)electromagnetic
B)chemical
C)mechanical
D)sound

Question 41

What is the main adaptive advantage of the C₄ and CAM photosynthesis strategies over the C₃ strategy?

A)They help the plant synthesize glucose efficiently under dry conditions.
B)They allow the plant to fix carbon under conditions of low CO₂.
C)They allow the plant to fix carbon in cool conditions.
D)They make it possible for the plant to use the Calvin cycle at night.

Question 42

Plant cells

A)lack mitochondria and chloroplasts.
B)lack mitochondria but have chloroplasts.
C)have mitochondria but do not have chloroplasts.
D)have mitochondria and chloroplasts.

Question 43

Plants use sugars as

A)a fuel for photosynthesis.
B)a starting material for the Calvin cycle.
C)a source of electrons for chemiosmosis.
D)a fuel for cellular respiration and a starting material for making other organic molecules.

Question 44

Photophosphorylation during photosynthesis differs from oxidative phosphorylation during cellular respiration in that

A)it involves an electron transport chain.
B)energy is stored in the form of a proton (H⁺)concentration difference.
C)generation of ATP is driven by a flow of protons (H⁺)through ATP synthase.
D)the final electron acceptor is NADP⁺ and not oxygen.

Question 45

The Calvin cycle constructs ________, an energy-rich molecule that a plant cell can then use to make glucose or other organic molecules.

A)G3P
B)ATP
C)NADH
D)carbon dioxide

Question 46

To produce one glucose, the Calvin cycle needs to be run ________ times.

A)two
B)four
C)six
D)eight

Question 47

The ultimate source of all the food we eat and the oxygen we breathe is

A)cellular respiration.
B)photosynthesis.
C)glycolysis.
D)anaerobic metabolism.

Question 48

Photosynthetic organisms derive their carbon from

A)carbon monoxide.
B)carbon dioxide.
C)hydrocarbons.
D)methane.

Question 49

Which of the following statements about the greenhouse effect is true?

A)The greenhouse effect is reduced by deforestation.
B)The greenhouse effect is exacerbated by the use of fossil fuels.
C)The greenhouse effect will decrease the average temperature of the planet.
D)The greenhouse effect has no direct relationship with the Industrial Revolution of the 1800s.

Question 50

In photophosphorylation, energy from electron flow is used to transport ________ from the ________ to the thylakoid compartment, generating a concentration gradient of ________.

A)electrons; grana; H⁺
B)H⁺; grana; electrons
C)H⁺; stroma; H⁺
D)H⁺; stroma; ATP

Question 51

The addition of oxygen instead of carbon dioxide to RuBP results in

A)cellular respiration.
B)photorespiration.
C)photophosphorylation.
D)aerobic respiration.

Question 52

Photosystem II

A)receives electrons from photosystem I.
B)passes electrons to photosystem I.
C)does not have a reaction center.
D)releases CO₂ as a by-product.

Question 53

The electrons lost from the reaction center of photosystem II are replaced by electrons from

A)CO₂.
B)ATP.
C)H₂O.
D)photosystem I.

Question 54

ATP and NADPH

A)power sugar synthesis during the Calvin cycle.
B)are products of the Calvin cycle.
C)provide energy to photosystem I and photosystem II.
D)are used in the electron transport chain to pump H⁺ into the thylakoid space.

Question 55

In chloroplasts, ATP synthase

A)catalyzes the Calvin cycle.
B)phosphorylates ADP to ATP.
C)is found in the stroma.
D)helps produce the concentration gradient of H⁺.

Question 56

Photorespiration

A)may be an evolutionary relic from when atmospheric O₂ levels were low.
B)is of benefit to the plant since it breaks down rubisco.
C)is attributable to high CO₂ levels.
D)produces glucose.

Question 57

The electrons lost from the reaction center of photosystem I are replaced by electrons from

A)CO₂.
B)H₂O.
C)ATP.
D)photosystem II.

Question 58

Mitochondria transfer ________ energy from ________ to ATP; chloroplasts transform ________ energy into the chemical energy of ATP.

A)chemical; food; light
B)food; light; chemical
C)light; food; kinetic
D)food; light; nuclear

Question 59

Global warming due to the greenhouse effect may be

A)moderated by photosynthesis, which removes carbon dioxide from the atmosphere.
B)made worse by photosynthesis, which adds carbon dioxide to the atmosphere.
C)reduced by the burning of fossil fuels, which removes oxygen from the atmosphere.
D)of little concern, since it is part of the normal cycle for the planet.

Question 60

In photosynthesis, the chemiosmotic production of ATP

A)requires oxygen.
B)is similar to the production of ATP in mitochondria.
C)is done by the Calvin cycle.
D)is a result of the oxidation of glucose.

Question 61

According to this figure, how do hydrogen ions make their way from the stroma to the thylakoid interior?

A)through photosystem I
B)through an electron transport chain molecule
C)through the ATP synthase
D)directly through the phospholipids of the thylakoid membrane

Question 62

After reading the paragraph below, answer the questions that follow.
The graph below shows records of temperature (light gray line) and CO₂ (dark gray line) over the past 1,000 years. CO₂ is recorded in parts per million (ppm).

If the trends shown in the graph continue, how might this affect photosynthesis?

A)Photorespiration may increase, leading to an increase in photosynthetic production of sugar.
B)Photorespiration may increase, leading to a decrease in photosynthetic production of sugar.
C)C₄ and CAM plants would be unable to photosynthesize.
D)There would be no effect on photosynthesis, since CO₂ and temperature are stable.

Question 63

After reading the paragraph below, answer the questions that follow.
The graph below shows records of temperature (light gray line) and CO₂ (dark gray line) over the past 1,000 years. CO₂ is recorded in parts per million (ppm).

If you focus on the data from the mid-1900s (indicated by the arrow)through today, the graph shows that

A)there is a correlation between CO₂ and temperature; when CO₂ levels are high, so is temperature.
B)there is a correlation between CO₂ and temperature; when CO₂ levels are high, temperature is low.
C)there is no correlation between CO₂ and temperature; CO₂ fluctuates randomly and temperature is constant.
D)there is no correlation between CO₂ and temperature; CO₂ is constant and temperature fluctuates randomly.

Question 64

After reading the paragraph below, answer the questions that follow.
The graph below shows records of temperature (light gray line) and CO₂ (dark gray line) over the past 1,000 years. CO₂ is recorded in parts per million (ppm).

Currently, atmospheric CO₂ levels are approximately 400 ppm. The annual mean growth rate in CO₂ is about 2 ppm/year. Assuming this trend continues, what would you predict the CO₂ level to be in 100 years?

A)100 ppm
B)200 ppm
C)600 ppm
D)1,000 ppm

Question 65

It has been suggested that global warming could be halted by fertilizing the oceans to increase the growth of algae. How might this affect the greenhouse effect?

A)Algal photosynthesis would use up more CO₂, which traps heat.
B)Algal photosynthesis would produce more O₂, which blocks light.
C)Algal photosynthesis would be inhibited by the addition of fertilizer.
D)Algae photosynthesis would use heat in place of photons.

Question 66

Purple sulfur bacteria are organisms capable of photosynthesis. They get their name, in part, because they use H₂S (hydrogen sulfide)instead of water during the light reactions. In what form would you expect to find sulfur (S)as a result of photosynthesis in these bacteria?

A)S₂
B)SO₂
C)CS₂
D)C₆H₁₂S₆

Question 67

Atrazine is a widely used herbicide that binds to a protein in photosystem II, ultimately causing a breakdown in electron transport. Atrazine would first inhibit the production of

A)NADPH.
B)G3P.
C)ATP.
D)O₂.

Question 68

Put the following steps of the Calvin cycle in the correct order: 1. Carbon fixation
2) Regeneration of RuBP
3) Release of G3P
4) Reduction

A)1, 2, 3, 4
B)1, 3, 4, 2
C)1, 4, 3, 2
D)4, 1, 2, 3

Question 69

Put the following steps of the light reactions in the correct order: 1. Light excites an electron from photosystem I.
2) Light excites an electron from photosystem II.
3) Electrons reduce NADP⁺ to NADPH.
4) Electrons pass through an electron transport chain, which generates a H⁺ gradient used to make ATP.

A)1, 2, 3, 4
B)1, 4, 2, 3
C)2, 4, 1, 3
D)2, 3, 1, 4

Question 70

Ozone consists of ________ oxygen atom(s).

A)one
B)two
C)three
D)four

Question 71

Which of the following is not an expected outcome of global climate change?

A)extreme weather patterns
B)lower sea levels
C)spread of tropical diseases
D)increased extinction rates

Question 72

In this drawing of a chloroplast, which structure represents the thylakoid membrane?

A)structure A
B)structure B
C)structure C
D)structure D

Question 73

Which of the following has been a major source of ozone destruction over the past 50 years?

A)chlorofluorocarbons (CFCs)
B)ethylene glycol (C₂H₆O₂)
C)carbon dioxide (CO₂)
D)methane (CH₄)

Question 74

It has been argued that cutting old-growth forests and replacing them with plantations of young trees would help to alleviate the threat of global greenhouse warming. What important fact does this argument ignore?

A)Forests play too minor a role in global CO₂ dynamics, which are affected far more by marine algae.
B)Young trees fix carbon at a lower rate per unit mass than old trees.
C)Most of the biomass of the cut trees would be added to the atmosphere as CO₂ within a few years.
D)Most of the young trees would die within a few years.

Question 75

Chlorophyll is located in ________, which are found in ________, which are concentrated in ________.

A)thylakoids; chloroplasts; mesophyll
B)chloroplasts; thylakoids; mesophyll
C)mesophyll; chloroplasts; thylakoids
D)mesophyll; thylakoids; chloroplasts

Question 76

You want to use radioactively labeled oxygen to trace carbon fixation in a plant. You should incorporate the radioactively labeled oxygen into

A)O₂.
B)CO₂.
C)H₂O.
D)C₆H₁₂O₆.

Question 77

Red algae are found in relatively deep water. In order for light to penetrate to these depths, it must be high in energy. Which wavelengths of light would you expect red algae to use?

A)red
B)yellow
C)green
D)blue

Question 78

After reading the paragraph below, answer the questions that follow.
You're conducting an experiment to determine the effect of different wavelengths of light on the absorption of carbon dioxide as an indicator of the rate of photosynthesis in aquatic ecosystems. If the rate of photosynthesis increases, the amount of carbon dioxide in the environment will decrease, and vice versa.
Small aquatic plants are placed into three containers of water mixed with carbon dioxide. Container A is placed under normal sunlight, B under green light, and C under red light. The containers are observed for a 24-hour period.
Based on your knowledge of the process of photosynthesis, the plant in the container placed under red light would probably

A)absorb no CO₂.
B)absorb the same amount of CO₂ as the plants under the green light.
C)absorb less CO₂ than the plants under the green light.
D)absorb more CO₂ than the plants under the green light.

Question 79

Many of the regions of the world where hunger is prevalent are also regions with hot and dry climates. What types of agricultural crops would you suggest that these regions attempt to grow?

A)C₃ plants, such as wheat and rice
B)C₃ plants and C₄ plants, such as corn and sugarcane
C)C₃ plants and CAM plants, such as prickly pear and pineapple
D)C₄ plants and CAM plants

Question 80

Ozone

A)formation is promoted by CFCs.
B)is broken down by carbon dioxide.
C)is a source of oxygen for cellular respiration.
D)protects Earth from ultraviolet radiation.