Question 1

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.
-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 2

The electron transport chains of the light reactions

Accepted Answer

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 3

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?

Accepted Answer

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

Question 4

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

Accepted Answer

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

Question 5

________ cells in leaves are specialized for photosynthesis.

Accepted Answer

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

Question 6

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 7

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) synthesizers 
D) autotrophs

Question 8

Sunlight is a type of ________ energy.

Accepted Answer

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

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 not an expected outcome of global climate change?

Accepted Answer

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

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

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

Accepted Answer

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 13

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

Accepted Answer

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 14

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

Accepted Answer

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

Question 15

Which of the following is part of the light reaction?

Accepted Answer

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

Question 16

CO₂ enters and O₂ escapes from a leaf via

Accepted Answer

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

Question 17

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 18

Chlorophyll b

Accepted Answer

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 19

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 20

Which of the following molecules is a reactant of photosynthesis?

Accepted Answer

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

Exam 7: Photosynthesis: Using Light to Make Food