Deck 7: Photosynthesis: Using Light to Make Food

Question 1

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

Answer 1

D

Question 2

Where is chlorophyll found in a plant cell?

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

Answer 2

B

Question 3

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

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

Answer 3

A

Question 4

Autotrophs that utilize light as their energy source are

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

Question 5

Which of the following is an example of a photoautotroph?

A) grass on the front lawn
B) grizzly bears in Alaska
C) bacteria in our mouths
D) mushrooms growing on the side of a dead tree

Question 6

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

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

Question 7

Thylakoids are arranged in stacks called

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

Question 8

Which of the following molecules is a reactant of photosynthesis?

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

Question 9

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 10

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 11

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 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

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 14

CO2 enters and O2 escapes from a leaf via

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

Question 15

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 16

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 17

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) autotrophs

Question 18

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 19

________ cells in leaves are specialized for photosynthesis.

A) Stomata
B) Mesophyll
C) Vein

Question 20

A redox reaction involves the transfer of

A) oxygen.
B) water.
C) an electron.
D) a proton

Question 21

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 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 colors contributes the least energy to photosynthesis?

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

Question 24

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 25

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 26

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 27

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 28

Sunlight is a type of ________ energy.

A) electromagnetic
B) chemical
C) mechanical

Question 29

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

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

Question 30

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 31

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 32

As a result of the cascade of electrons moving down the electron transport chain and leaving 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 33

The energy that excites the photosystems is supplied by

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

Question 34

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

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

Question 35

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 36

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 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

An electron transport chain of the light reactions

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

Question 39

A packet of light energy is called a

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

Question 40

Which of the following molecules are products of photosynthesis?

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

Question 41

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

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

Question 42

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 43

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 44

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 45

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 46

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 47

Plants use sugars as a

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

Question 48

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 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 decreases plant growth.

Question 50

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 51

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 52

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 53

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

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

Question 54

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 55

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 56

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 57

Photosynthetic organisms derive their carbon from

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

Question 58

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 59

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 60

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 61

After reading the paragraph below, answer the questions that follow.
The graph 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 62

Which of the following best describes the transfer of energy and matter in photosynthesis?

A) Energy in sunlight directly becomes ATP molecules in photosynthesis.
B) ATP is made up of chemical energy which is transferred to sugar.
C) Energy in sunlight is transformed into chemical energy when electrons move to a more excited state.
D) Matter in ATP is transferred to sugars in photosynthesis when electrons from ATP become part of sugars.

Question 63

It has been suggested that scientists mimic photosynthesis by building artificial leaves that can respond to electricity from solar cells. The electricity could be applied to the leaves to split water into oxygen and hydrogen. The hydrogen could then be used a fuel. Which of these is the best explanation of how this mimics photosynthesis?

A) Both this proposed process and photosynthesis store solar energy as electricity for later use.
B) Both this proposed process and photosynthesis split water into hydrogen and oxygen.
C) The mimic leaves would have to be green like photosynthesizing leaves in order to respond to light.
D) Both processes convert electrical energy to light energy.

Question 64

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 65

Which of the following is the best summary of the process of photosynthesis?

A) Plants turn sunlight into sugars.
B) The majority of the mass of plant-made sugars comes from water and nutrients from the soil.
C) The majority of the mass of plant-made sugars comes from the atmosphere.
D) Plants make sugars by breaking down other organic molecules and using those components to make sugars.

Question 66

It has been suggested that scientists should attempt to genetically engineer a plant to have black leaves so that it would perform photosynthesis more efficiently. What is the likely reason behind this idea?

A) Black plants would heat up faster and therefore all chemical reactions including photosynthesis would operate faster.
B) A black plant would reflect all wavelengths and therefore have more energy to drive photosynthesis.
C) A black plant would absorb all wavelengths and therefore absorb more light energy that powers photosynthesis.
D) A black plant would absorb green wavelengths like most plants, but would absorb them more efficiently.

Question 67

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 68

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 69

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 70

What likely caused the slight increase of mean poison ivy biomass in the control plots?

A) random experimental error
B) an increase in atmospheric CO2 levels
C) There were more poison ivy plants in the control plots to begin with.

Question 71

Which of these can be concluded from the figure below?

A) In some years of the study the mean poison ivy biomass decreased to the level it was at the beginning of the study.
B) There were more elevated CO2 plots than control plots.
C) Not all of the increase in mean poison ivy biomass can be attributed to the CO2 that the researcher added.
D) Poison ivy in the experimental plots was more toxic than that in the control plots.

Question 72

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 73

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 74

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 75

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 76

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 77

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 78

After reading the paragraph below, answer the questions that follow.
The graph 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 79

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 80

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