Deck 8: Photosynthesis

Question 1

During the carbon cycle, plants and some other organisms "fix carbon-containing molecules, while other organisms eat those molecules and release CO₂. During the carbon cycle, CO₂ is produced during ________ and fixed during ________.

A) aerobic respiration; photosynthesis
B) aerobic respiration; photosynthesis and aerobic respiration
C) photosynthesis; aerobic respiration
D) aerobic respiration and photosynthesis; aerobic respiration
E) aerobic respiration; aerobic respiration

Answer 1

aerobic respiration; photosynthesis

Question 2

Refer to the figure above and then answer the question that follows.

-Plant leaves appear green because they ________ light spectrum.

A) scatter all colors except the green wavelength of the visible
B) scatter the green wavelength of the visible
C) absorb the green wavelength of the visible
D) scatter the green wavelength of the ultraviolet
E) absorb the green wavelength of the ultraviolet

Answer 2

scatter the green wavelength of the visible

Question 3

Refer to the figure above and then answer the question that follows.

-You have isolated a new plant that has yellow leaves. What color(s) is/are being absorbed?

A) yellow
B) all colors, including yellow
C) all colors except yellow
D) No colors are absorbed; they are only scattered.

Answer 3

all colors except yellow

Question 4

Refer to the figure above and then answer the question that follows.

-Which of the following statements about photosynthesis is FALSE?

A) Sunlight excites electrons from chlorophyll, which are captured by an electron acceptor that is down the energy hill.
B) During the light reactions, the ATP and NADPH are used to fix CO₂.
C) Photosynthesis involves many redox reactions similar to the electron transport chain used during respiration.
D) During the light reactions, ATP and NADPH are synthesized.
E) The end products of photosynthesis are glucose and O₂.

Question 5

Refer to the figure above and then answer the question that follows.

-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.

Question 6

Refer to the figure above and then answer the question that follows.

-The function of the stomata is to:

A) contain the chloroplasts.
B) fix CO₂.
C) let CO₂ into the leaf.
D) absorb the energy in light.

Question 7

Refer to the figure above and then answer the question that follows.

-What actually absorbs the light used to drive photosynthesis?

A) stomata
B) chloroplasts
C) thylakoids
D) grana
E) chlorophyll

Question 8

Refer to the figure above and then answer the question that follows.

-When white light strikes a blue shirt, blue light is:

A) reduced.
B) absorbed.
C) reflected or transmitted.
D) used to synthesize ATP.
E) converted to chemical energy.

Question 9

Refer to the figure above and then answer the question that follows.

-The expression "We are creatures of the chloroplasts means that:

A) all life depends ultimately on photosynthesis.
B) all life possesses chloroplasts.
C) chloroplasts are models of all organelles.

Question 10

Refer to the figure above and then answer the question that follows.

-Plants are particular about the type of light they can use for photosynthesis. If you were to use a filter on a light so that the plant received only green wavelengths of light, what would you expect to happen?

A) The light reactions of photosynthesis should happen really fast.
B) The light reactions of photosynthesis should speed up.
C) The light reactions of photosynthesis should slow way down.

Question 11

Refer to the figure above and then answer the question that follows.

-You just purchased a really cool lamp that has a yellow plastic shade that surrounds the light bulb. You put a plant under the lamp, but it dies within a week. What has happened?

A) Something is wrong with the plant's chlorophyll.
B) The yellow light produced by the lamp can't be utilized for photosynthesis.
C) Plants can't live under artificial light.

Question 12

Which of the following explains why plants create O₂?

A) During CO₂ fixation, they create O₂.
B) When they respire, they create O₂.
C) They create O₂ when they drink H₂O.
D) During the light reactions, they create O₂ when H₂O donates electrons to photosystem II.

Question 13

What is the function of H₂O in photosynthesis?

A) to serve as an electron acceptor
B) to donate electrons directly to chlorophyll
C) to provide oxygen for the photosynthetic organism to use during oxidation reactions
D) to donate electrons directly to NADP
E) to oxidize NADPH

Question 14

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, causing an electron acceptor down the energy hill to accept them.
C) Sunlight excites electrons in chlorophyll, allowing an electron acceptor up the energy hill to accept them.

Question 15

During photosynthesis, what molecule donates electrons to chlorophyll to replace the electrons excited by sunlight?

A) NADPH
B) O₂
C) H₂O
D) NADH
E) CO₂

Question 16

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

Question 17

Which of the following statements about photosynthesis is false?

A) NADP is reduced.
B) Water is oxidized.
C) FADH is oxidized.
D) Solar energy drives the reactions.

Question 18

If plants evolved to use H₂S instead of H₂O to replenish the electrons in chlorophyll during photosynthesis, how would this affect humans?

A) We would not be able to carry out fermentation.
B) We would not be able to carry out cellular respiration.
C) We would not have sugar to eat.
D) It would have no effect.

Question 19

Plants make ATP during the light reactions of photosynthesis. Why do they also need to carry out the process of cellular respiration?

A) The ATP made is photosynthesis is different from the ATP made in cellular respiration.
B) The ATP made is photosynthesis is only enough to fuel the light reactions. The plant has to carry out cellular respiration to make large amounts of ATP.
C) Plants need to make ATP from cellular respiration only when the conditions for photosynthesis are bad.
D) Plants do not ever need to perform cellular respiration.

Question 20

During photosynthesis, energy is released and is used to create ATP when:

A) electrons are passed down the energy hill during the light reactions
B) electrons are passed down the energy hill during the light reactions.
C) CO₂ is fixed into sugars in the light reactions.
D) water is split, releasing oxygen.
E) CO₂ is fixed into sugars during the light reactions.

Question 21

When NADP is converted into NADPH during photosynthesis, this is ________ reaction.

A) an oxidation
B) neither an oxidation nor a reduction
C) either an oxidation or a reduction
D) a reduction

Question 22

If you put a plant in the dark, it cannot:

A) fix H₂O into sugars.
B) perform respiration.
C) perform fermentation.
D) fix CO₂ into sugars.

Question 23

During the light reactions of photosynthesis,

A) the Krebs cycle occurs.
B) CO₂ is fixed into organic molecules.
C) H₂O is oxidized to oxygen.
D) glycolysis occurs.

Question 24

Refer to the figure above and then answer the question that follows.

-Bundle sheath cells are used to:

A) fix CO₂ in C₄ plants.
B) store CO₂ in C₄ plants.
C) fix CO₂ in C₃ plants.
D) store CO₂ in C₃ plants.
E) fix and store CO₂ in C₃ plants.

Question 25

Refer to the figure above and then answer the question that follows.

-C₄ plants don't perform photorespiration; therefore, they can keep their stomata closed longer when the weather is warm. This seems to be an advantage. Why aren't all plants C₄ plants? Refer to the figure above for help.

A) C₄ plants can't take in any oxygen while the stomata are closed.
B) C₄ plants must use ATP to shuttle CO₂ to the bundle-sheath cells.
C) C₄ plants can't take any CO₂ while the stomata are closed.
D) C₄ plants can't take in any water while the stomata are closed.

Question 26

Refer to the figure above and then answer the question that follows.

-Referring to the figure above, a C₄ plant is different from a C₃ plant because it:

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.

Question 27

How did scientists determine the intermediates of the Calvin cycle?

A) They watched where the CO₂ went through a microscope.
B) They watered plants with ¹⁴C-labeled water.
C) They exposed plants to ¹⁴C-labeled CO₂.
D) They watched where the CO₂ went through an electron microscope.
E) They fed plants ¹⁴C-labeled sugars.

Question 28

Carbon dioxide is a greenhouse gas that is thought to be responsible for global warming. Using this information, explain why destruction of the Earth's rain forests is thought to be contributing to global warming.

Question 29

Describe how the electron transport chain of respiration and photosynthesis are similar.

Question 30

In many areas, if you look around outside during the fall, you will notice that trees are beginning to change colors and that their leaves are dropping. Explain the following:

A) Given that the plants no longer have green leaves, what are they lacking at this point? Without this item, what are the plants unable to do?
B) Given that the plants can no longer perform this function, what process will the plants carry out throughout the winter to keep them alive until they regain leaves in the spring? What will be the fuel for this process?

Question 31

Your boss at a biotech firm wants you to create a plant that lacks chlorophyll. Explain to your boss what this plant will be unable to do and whether you think such a plant can live. If not, why?

Question 32

If plants were unable to fix CO₂, what would be the result for humans?

Question 33

If all animals died, explain how plants and photosynthesis would be affected. Your answer should address how and why animals and plants are dependent on each other, as well as how the specifics of photosynthesis would be affected.

Question 34

If you could develop a plant that was unable to perform photorespiration, how would this discovery affect humans? Would such a plant be able to survive? If not, why?