Question 1

In chloroplasts, ATP synthase

Accepted Answer

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 2

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?

Accepted Answer

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 3

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

Accepted Answer

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

Question 4

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

Accepted Answer

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 5

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.

Accepted Answer

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

Question 6

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

Accepted Answer

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 7

In photosynthesis, the chemiosmotic production of ATP

Accepted Answer

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 8

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.
-Carbon dioxide absorption is an appropriate indicator of photosynthesis because

Accepted Answer

A)  CO2 is needed to produce sugars in the Calvin cycle. 
B)  CO2 is needed to complete the light reactions. 
C)  plants produce oxygen gas by splitting CO2. 
D)  the energy in CO2 is used to produce ATP and NADPH.

Question 9

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?

Accepted Answer

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 10

Which of the following is an example of a photoautotroph?

Accepted Answer

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 11

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

Accepted Answer

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 12

Photosynthetic organisms derive their carbon from

Accepted Answer

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

Question 13

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?

Accepted Answer

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

Question 14

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

Accepted Answer

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

Question 15

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

Accepted Answer

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 16

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

Accepted Answer

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 17

Why are most plants green?

Accepted Answer

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 18

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

Accepted Answer

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

Question 19

Carbon fixation

Accepted Answer

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 20

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?

Accepted Answer

A)  chemotrophs 
B)  heterotrophs 
C)  autotrophs

Exam 7: Photosynthesis: Using Light to Make Food