Deck 5: Photosynthesis

Question 1

Visible light comprises wavelengths that vary between ____ nanometers.

A) 380 and 750
B) 350 and 750
C) 390 and 780
D) 340 and 740
E) 320 and 740

Answer 1

A

Question 2

Most of the colors we see around us result from ____.

A) reflected light
B) direct sunlight
C) absorbed light
D) the inherent color of the objects we are looking at
E) a combination of absorbed and reflected light

Answer 2

A

Question 3

Fossil fuels ____.

A) can be recycled
B) are produced by living organisms
C) are the organic remains of ancient organisms
D) can reduce climate change
E) release less energy than wood when they are burned

Answer 3

C

Question 4

Which component is NOT found in a chloroplast?

A) a single outer membrane
B) DNA
C) ribosomes
D) stroma
E) thylakoids

Question 5

Pigments are ____.

A) inorganic molecules that absorb all light
B) organic molecules that absorb all light
C) inorganic molecules that absorb specific wavelengths of light
D) organic molecules that absorb specific wavelengths of light
E) inorganic molecules that reflect specific wavelengths of light

Question 6

The main producer(s) for the human food chain is/are ____.

A) farmers
B) light
C) plants
D) cows
E) methane

Question 7

If a pigment absorbed violet, yellow, orange, red, and green light, what color would it appear to be?

A) white
B) brown
C) black
D) blue
E) gray

Question 8

In which cellular organelle does photosynthesis take place?

A) rough endoplasmic reticulum
B) Golgi bodies
C) mitochondria
D) chloroplasts
E) lysosome

Question 9

In which of the following do the light-dependent reactions of photosynthesis take place?

A) thylakoid membranes
B) stroma
C) the outermost membrane
D) between the outermost and innermost membranes
E) a combination of more than one of these

Question 10

Leaves appear red in the fall when ____.

A) anthocyanin synthesis increases
B) chlorophylls are disassembled and recycled to allow other pigments to become more visible
C) other pigments, including the orange and yellow accessory pigments, are recycled
D) synthesis of other pigments, including the orange and yellow accessory pigments, increases
E) the red wavelength range of visible light increases due to changes in Earth's position relative to the sun

Question 11

The membrane that forms a compartment inside the stroma is the ____.

A) thylakoid
B) mitochondrion
C) lamella
D) plastid
E) tracheid

Question 12

Photosynthesis converts the energy of light into ____.

A) pigments
B) chemical bond energy
C) proteins
D) electrons and protons
E) heat energy

Question 13

The human body is about ____ percent carbon by weight.

A) 0.0095
B) 0.095
C) 0.95
D) 9.5
E) 95

Question 14

Chlorophyll a molecules absorb ____ light.

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

Question 15

The energy that drives the light-independent reactions comes from ____.

A) sunlight
B) glucose
C) carbon dioxide
D) ATP and NADPH
E) water and oxygen

Question 16

We know that carbon dioxide levels were in the atmosphere millions of years ago through ____.

A) radioisotope dating
B) measuring carbon dioxide levels in fossil fuel samples
C) measuring carbon isotope ratios in fossil fuel samples
D) measuring carbon dioxide levels in air pockets in ice cores
E) measuring carbon isotope ratios in air pockets in ice cores

Question 17

The conversion of solar energy into chemical energy occurs during ____.

A) glycolysis
B) photosynthesis
C) respiration
D) fermentation
E) chemosynthesis

Question 18

The distance between the crests of two successive waves of light is known as the ____.

A) wave frequency
B) wave period
C) wave distance
D) wavelength
E) wave space

Question 19

According to evidence from ice layers from the Antarctic, atmospheric carbon dioxide levels have been rising since ____.

A) the dinosaurs went extinct
B) about 10,000 years ago
C) the industrial revolution began
D) the 1970s
E) the evolution of humans 200,000 years ago

Question 20

The stroma of a chloroplast is most like which cellular structure?

A) ribosome
B) cell membrane
C) the cytoplasm
D) nuclei
E) mitochondrion

Question 21

ATP is formed when ____ the thylakoid compartment.

A) hydrogen ions enter
B) hydrogen ions leave
C) electrons leave
D) electrons enter
E) water is split in

Question 22

Which group of molecules serves as inputs for the light-independent reactions?

A) H₂O, ATP, and NADPH
B) CO₂, NADPH, and H₂O
C) CO₂ and NADPH
D) ATP, NADPH, H₂O, and CO₂
E) NADPH, ATP, and CO₂

Question 23

The purpose of a photosystem is to convert ____.

A) light energy into chemical energy
B) carbon dioxide into sugar
C) light energy into sugar
D) oxygen into carbon dioxide
E) light into oxygen

Question 24

Which source of energy powers the light-independent reactions of photosynthesis?

A) light
B) ATP and NADPH
C) photosystem II
D) glucose
E) NADP⁺

Question 25

How many carbon dioxide molecules does it take to synthesize one molecule of glucose?

A) 2
B) 4
C) 6
D) 12
E) 18

Question 26

Hydrogen ion flow out of the thylakoid compartments ____.

A) occurs between photosystems I and II
B) is called the hydrogen transfer system
C) provides energy to produce ATP molecules
D) causes excitation of molecules
E) requires the intermediary action of acceptor molecules

Question 27

The electrons that are passed to NADP⁺ at the end of the electron transfer chain were obtained from ____.

A) water
B) CO₂
C) glucose
D) sunlight
E) ATP

Question 28

Light-independent reactions occur in the ____.

A) cytoplasm
B) chloroplast outer membrane
C) thylakoid membrane
D) stroma
E) matrix

Question 29

When chlorophyll absorbs light energy, ____.

A) chlorophyll is converted to carotene
B) the molecules begin to move more rapidly
C) the plant becomes radioactive
D) electrons jump to a higher energy level
E) the molecules become ionized

Question 30

What powers the ATP synthase enzyme in the light-dependent reactions of photosynthesis?

A) energy from ATP
B) energy from NADPH
C) energy from the splitting of water
D) energy from electron transfer chains
E) energy from the flow of hydrogen ions

Question 31

The products of light-dependent reactions of photosynthesis are ____.

A) used in light-independent reactions
B) complex carbohydrates and proteins
C) stored in the vacuoles of the cell
D) oxygen and glucose
E) used in the light-independent reactions and stored in the vacuoles of the cell

Question 32

The carbon dioxide acceptor in the Calvin-Benson cycle of photosynthesis is ____.

A) phosphoglycerate (PGA)
B) ribulose bisphosphate (RuBP)
C) phosphoglyceraldehyde (PGAL)
D) glucose
E) phosphoenolpyruvate

Question 33

The energy generated in the first electron transfer chain in the light-dependent reactions of photosynthesis is used to ____.

A) split water into oxygen, hydrogen ions, and electrons
B) generate NADPH
C) power the ATP synthase enzyme to produce ATP
D) pump hydrogen ions into the thylakoid compartment
E) generate glucose

Question 34

Plant cells produce oxygen gas ____.

A) by splitting carbon dioxide
B) during respiration
C) by splitting ribulose bisphosphate
D) by splitting molecules of water
E) by breaking down glucose

Question 35

The primary purpose of splitting the water in the light-dependent reactions of photosynthesis is to ____.

A) release oxygen for aerobic respiration
B) generate ATP
C) generate NADH
D) actively transfer hydrogen ions across the thylakoid membrane
E) release electrons for electron transport phosphorylation

Question 36

Which of the following molecule(s) is/are formed at the end of the electron transfer process?

A) ATP only
B) NADPH only
C) ATP and NADPH
D) NADP⁺
E) ATP and NADP⁺

Question 37

In the light-dependent reactions of photosynthesis, NADP⁺ gets its electrons to become NADPH from ____.

A) ATP synthase
B) the flow of hydrogen ions
C) electron transfer chains
D) oxygen gas
E) glucose

Question 38

In the light-dependent reactions of photosynthesis, how do hydrogen ions get back into the stroma?

A) passive diffusion directly across the thylakoid membrane
B) active transport across the thylakoid membrane
C) facilitated diffusion across the thylakoid membrane
D) active transport through ATP synthase
E) passive diffusion through ATP synthase

Question 39

The Calvin-Benson cycle is a cyclical pathway of reactions that use ____.

A) carbon to produce sugar
B) sugar to produce energy
C) sugar to produce starch
D) starch to produce energy
E) oxygen to produce carbon dioxide

Question 40

In light-dependent reactions, hydrogen ions are transported into the thylakoid membrane. What drives the movement of these ions?

A) passive diffusion of ions from high to low concentration
B) passive diffusion of ions from low to high concentration
C) active transport of ions driven by the hydrolysis of water into oxygen
D) active transport of ions driven by energy from the electron transport chain
E) active transport through the enzyme ATP synthase

Question 41

The most direct product of the Calvin-Benson cycle, which can be used to continue to cycle but which is also exported for other uses such as glucose synthesis, is ____.

A) PGAL
B) PGA
C) RuBP
D) NADPH
E) ATP

Question 42

You are a botanist living in the desert. A friend asks you which plant would be most practical to plant in his or her yard. What is your answer?

A) any plant, as long as it is well-watered
B) only plants that do not minimize photorespiration
C) only plants that minimize photorespiration
D) only plants that minimize photorespiration and close the stomata during the day
E) plants that do not minimize photorespiration or plants that do minimize photorespiration but not plants that close the stomata during the day

Question 43

In the thylakoid membrane, photosynthetic pigments are held together by ____.

A) enzymes
B) energy
C) proteins
D) chlorophyll
E) electrons

Question 44

Early organisms were anaerobic. As early organisms evolved the ability to harness energy from the sun, other organisms began to die out because they were ____.

A) destroyed by a meteorite
B) outcompeted by multicelled organisms
C) consumed by dinosaurs
D) poisoned by oxygen gas
E) starved

Question 45

Photorespiration ____ the efficiency of sugar production and ____ the amount of carbon fixation.

A) increases; increases
B) increases; decreases
C) decreases; increases
D) maintains; increases
E) decreases; decreases

Question 46

In the light-dependent reactions of photosynthesis, what is the ultimate fate of the electrons released from photosystem absorption of light energy?

A) They are combined with NAD⁺.
B) They are combined with ATP.
C) They become hydrogen ions.
D) They are moved through the electron transport chain.
E) They are combined with NADP⁺ and hydrogen ions to form NADPH.

Question 47

The purpose of closing stomata in plants is to prevent ____.

A) carbon dioxide from escaping
B) water from escaping
C) oxygen from reentering
D) gas exchange
E) photosynthesis

Question 48

Consider Calvin-Benson cycle. What is the correct sequence in the series of reactions?
I) carbon fixation
II) regeneration
III) reduction

A) I → II → III
B) I → III → II
C) II → I → III
D) II → III → I
E) III → I → II

Question 49

For six molecules of carbon dioxide fixed in the light-independent reaction, how many molecules of PGA are produced?

A) 2
B) 4
C) 6
D) 12
E) 18

Question 50

The enzyme that fixes carbon dioxide into the Calvin-Benson cycle is ____.

A) rubisco
B) carbon dioxide oxidase
C) ATP synthase
D) carbon hydrogenase
E) RuBP

Question 51

Which of the following is the correct order of wavelengths from lowest to highest energy?

A) radio waves, microwaves, ultraviolet radiation, X-rays, gamma rays
B) gamma rays, X-rays, ultraviolet radiation, microwaves, radio waves
C) radio waves, ultraviolet radiation, microwaves, X-rays, gamma rays
D) gamma rays, ultraviolet radiation, X-rays, microwaves, radio waves
E) radio waves, ultraviolet radiation, X-rays, gamma rays, microwaves

Question 52

Why does the efficiency of sugar production decrease when stomata are closed in C3 plants?

A) Accumulated oxygen outcompetes carbon dioxide for rubisco's active site.
B) Depleted carbon dioxide outcompetes oxygen for rubisco's binding site.
C) Accumulated oxygen inhibits rubisco's function.
D) Depleted carbon dioxide inhibits rubisco's function.
E) Depleted carbon dioxide activates rubisco's function.

Question 53

How do plants compensate for rubisco's inefficiency at sugar production?

A) Plants make a large amount of the enzyme.
B) Plants fix the carbon twice at two different times of day.
C) Plants fix the carbon only once.
D) Plants store products in vacuoles.
E) Plants only fix carbon at night.

Question 54

During photosynthesis, cells extract energy from ____ to produce glucose.

A) oxygen
B) ATP
C) NADPH
D) water
E) sunlight

Question 55

How many PGA molecules (net yield) are produced per molecule of CO₂ during carbon fixation?

A) 1
B) 2
C) 4
D) 36
E) 38

Question 56

What are the advantages of plants that minimize photorespiration?

A) High sugar production can be maintained on hot, dry days.
B) Water is not necessary for the light-dependent reactions.
C) Carbon dioxide is not needed for the light-independent reactions.
D) Less sugar is necessary for metabolic activities.
E) Light-dependent reactions are more efficient.

Question 57

The Calvin-Benson cycle takes place in ____.

A) the cytoplasm
B) mitochondria
C) chloroplasts
D) thylakoids
E) peroxisomes

Question 58

What does beta-carotene do?

A) improve the efficiency pigments
B) act as coenzymes in glycolysis
C) neutralize free radicals
D) remove chlorophyll
E) enhance photosynthetic activity

Question 59

In most plants, glucose is stored as ____.

A) glucose
B) starch
C) sucrose
D) glycogen
E) cellulose

Question 60

When the stomata are closed, ____.

A) O₂ levels decline
B) CO₂ levels decline
C) CO₂ levels increase
D) efficiency of sugar production increases
E) PGAL increases

Question 61

In the thylakoid membrane, potential energy can be used to make ____.

A) pyruvate
B) NADH
C) fats
D) lactate
E) ATP

Question 63

What is the role of electron transfer phosphorylation in the light-dependent reactions of photosynthesis?

A) to provide electrons for NADH
B) to accept energy from glucose
C) to accept electrons from electron transport
D) to provide kinetic energy for ATP synthase
E) to donate electrons for electron transport

Question 64

How many turns of the Calvin-Benson cycle is required to produce one three-carbon sugar?

A) 3
B) 6
C) 12
D) 36
E) 40

Question 66

When trees or other plants burn, ____ is released into the atmosphere.

A) pyruvate
B) ethanol
C) acetaldehyde
D) acetyl CoA
E) lactate

Question 68

Which enzyme carries out carbon fixation during the Calvin-Benson cycle?

A) nitrogen
B) protease
C) carbon
D) rubisco
E) NADPH

Question 69

In the thylakoid membrane, the hydrogen gradient is a form of ____ energy.

A) kinetic
B) thermal
C) potential
D) chemical
E) electrical

Question 70

When organic molecules are broken and carbon dioxide is released into the atmosphere through burning, this is essentially the reverse of____.

A) photosynthesis
B) carbon fixation
C) the Calvin-Benson cycle
D) photorespiration
E) ATP production

Question 71

Which five-carbon molecule is the starting compound of the Calvin-Benson cycle?

A) PGA
B) RuBP
C) NADPH
D) carbon dioxide
E) ATP

Question 72

In cyanobacteria, light-dependent reactions are carried out by molecules in ____.

A) the thylakoid membrane
B) chloroplasts
C) stroma
D) stomata
E) outer membrane

Question 73

Which photosynthetic pigment is most efficient at absorbing near-infrared light?

A) chlorophyll a
B) chlorophyll b
C) chlorophyll f
D) beta-carotene
E) phycocyanin

Question 74

In a noncyclic pathway, photosystem II takes electrons from ___ in the thylakoid compartment.

A) oxygen
B) water
C) carbon dioxide
D) ethanol
E) hydrogen

Question 75

In the fall, ____ become(s) visible in plants that are preparing for dormancy.

A) accessory pigments
B) chlorophyll a
C) polysiphonia
D) gamma rays
E) radio waves

Question 76

In chloroplasts, the Calvin-Benson cycle occurs in ____.

A) pigments
B) the thylakoid membrane
C) the stomata
D) stroma
E) lysosomes

Question 77

Biofuels ____.

A) are a renewable source of energy
B) do not produce carbon dioxide when burned
C) are made from organic remains of ancient organisms
D) release energy without using oxygen
E) do not damage the environment

Question 78

Which of the following molecules is/are formed at the end of the electron transfer phosphorylation?

A) ATP
B) NADPH
C) ATP and NADPH
D) FADH₂
E) H₂O

Question 79

In a noncyclic pathway, ____ provides replacement electrons for photosystem I.

A) oxygen
B) photosystem II
C) carbon dioxide
D) water
E) hydrogen