Question 1

Figure 10.1 
-Which of the following are directly associated with photosystem I?
A)harvesting of light energy by ATP
B)receiving electrons from plastocyanin
C)P680 reaction-center chlorophyll
D)extraction of hydrogen electrons from the splitting of water
E)passing electrons to plastoquinone

Accepted Answer

Photosystem I receives electrons from plastocyanin, a protein in the thylakoid membrane. The other options are associated with photosystem II.

Question 2

Use the following information to answer the questions below.
Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light.
-If you ran the same experiment without passing light through a prism, what would you predict?
A)There would be no difference in results.
B)The bacteria would be relatively evenly distributed along the algal filaments.
C)The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
D)The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
E)The number of bacteria would decrease due to a decrease in the temperature of the water.

Accepted Answer

Without passing light through a prism, all segments of the algae will be exposed to the same wavelengths of light, resulting in a relatively even distribution of bacteria along the algal filaments.

Question 3

Figure 10.1 
-In the thylakoid membranes, what is the main role of the antenna pigment molecules?
A)split water and release oxygen to the reaction-center chlorophyll
B)harvest photons and transfer light energy to the reaction-center chlorophyll
C)synthesize ATP from ADP and Pi
D)transfer electrons to ferredoxin and then NADPH
E)concentrate photons within the stroma

Accepted Answer

The antenna pigment molecules in the thylakoid membranes are responsible for harvesting photons (light energy) and transferring them to the reaction-center chlorophyll. This process is known as light harvesting and is essential for photosynthesis.

Question 4

Use the following information to answer the questions below.
Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light.
-An outcome of this experiment was to help determine
A)the relationship between heterotrophic and autotrophic organisms.
B)the relationship between wavelengths of light and the rate of aerobic respiration.
C)the relationship between wavelengths of light and the amount of heat released.
D)the relationship between wavelengths of light and the oxygen released during photosynthesis.
E)the relationship between the concentration of carbon dioxide and the rate of photosynthesis.

Accepted Answer

The experiment of Theodor W. Engelmann helped determine the relationship between wavelengths of light and the oxygen released during photosynthesis. The experiment showed that the largest groups of bacteria were found in the areas illuminated by the red and blue light, indicating that these wavelengths were the most effective in producing oxygen through photosynthesis.

Question 5

When oxygen is released as a result of photosynthesis, it is a by-product of which of the following?
A)reducing NADP⁺
B)splitting the water molecules
C)chemiosmosis
D)the electron transfer system of photosystem I
E)the electron transfer system of photosystem II

Accepted Answer

Oxygen is released as a result of photosynthesis during the light reactions when water molecules are split into oxygen, electrons, and protons. This process occurs in photosystem II.

Question 6

What are the products of the light reactions that are subsequently used by the Calvin cycle?
A)oxygen and carbon dioxide
B)carbon dioxide and RuBP
C)water and carbon
D)electrons and photons
E)ATP and NADPH

Accepted Answer

The products of the light reactions, ATP and NADPH, are subsequently used by the Calvin cycle to convert carbon dioxide into sugar.

Question 7

Figure 10.1 
-Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?
A)Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
B)Bright sunlight destroys photosynthetic pigments.
C)Oxygen given off during photosynthesis interferes with the absorption of light.
D)Other pigments absorb light in addition to chlorophyll a.
E)Aerobic bacteria take up oxygen which changes the measurement of the rate of photosynthesis.

Accepted Answer

The absorption spectrum for chlorophyll a shows that it mainly absorbs red and blue wavelengths, but there are also some other pigments that absorb different wavelengths of light. The action spectrum for photosynthesis shows that it is most efficient at absorbing red and blue wavelengths, but also utilizes green and yellow wavelengths to a lesser extent. Therefore, the difference in the spectra can be attributed to other pigments in addition to chlorophyll a that absorb different wavelengths of light.

Question 8

A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?
A)red and yellow
B)blue and violet
C)green and yellow
D)blue, green, and red
E)green, blue, and yellow

Accepted Answer

The color of the leaves is determined by the wavelengths of light that are reflected, not absorbed. Since the leaves appear reddish yellow, it means that red and yellow wavelengths are being reflected, while the complementary colors, such as blue and violet, are being absorbed by the pigment.

Question 9

Figure 10.1 
-Which statement describes the functioning of photosystem II?
A)Light energy excites electrons in the electron transport chain in a photosynthetic unit.
B)The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit.
C)The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP⁺.
D)The electron vacancies in P680 are filled by electrons derived from water.
E)The splitting of water yields molecular carbon dioxide as a by-product.

Accepted Answer

Photosystem II is responsible for the initial photoexcitation of electrons in the electron transport chain of photosynthesis. The electrons are excited by light energy and then passed along the chain until they reach P700 chlorophyll in photosystem I. The electrons lost by P680 chlorophyll are replenished by electrons derived from the splitting of water, which yields O2 as a by-product.

Question 10

Use the following information to answer the questions below.
Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light.
-What did Engelmann conclude about the congregation of bacteria in the red and blue areas?
A)Bacteria released excess carbon dioxide in these areas.
B)Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
C)Bacteria congregated in these areas because these areas had the most oxygen being released.
D)Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.
E)Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.

Accepted Answer

Engelmann concluded that the bacteria congregated in the areas illuminated by red and blue light because those areas had the most oxygen being released due to photosynthesis by the algae.

Question 11

Figure 10.1 
-What wavelength of light in the figure is most effective in driving photosynthesis?
A)420 mm
B)475 mm
C)575 mm
D)625 mm
E)730 mm

Accepted Answer

The answer of Figure 10.1 
-What wavelength of light in...

Question 12

Where does the Calvin cycle take place?
A)stroma of the chloroplast
B)thylakoid membrane
C)cytoplasm surrounding the chloroplast
D)chlorophyll molecule
E)outer membrane of the chloroplast

Accepted Answer

The Calvin cycle takes place in the stroma of the chloroplast. This is the area surrounding the thylakoid membrane where the light-dependent reactions occur.

Question 13

Figure 10.1 
-Compared with the lines for chlorophyll a in the figure, where would you expect to find the lines to differ for chlorophyll b?
A)The absorption spectrum line would be lowest for chlorophyll b somewhat to the right of that for chlorophyll a (500-600).
B)The rate of photosynthesis line for chlorophyll b would be lowest from 600-700 nm.
C)The lines for the two types of chlorophyll would be almost completely opposite.
D)The lines for the two types of chlorophyll would be almost completely identical.
E)The peaks of the line for absorbance of b would be shifted to the left, and for rate of photosynthesis would be shifted to the right.

Accepted Answer

Chlorophyll b differs from chlorophyll a in its absorption spectrum, as it has a lower absorption peak at around 450-500 nm and a higher peak at around 600-650 nm. Therefore, the line for chlorophyll b in the absorption spectrum would be lowest somewhat to the right of that for chlorophyll a (500-600).

Question 14

In any ecosystem, terrestrial or aquatic, what group(s)is (are)always necessary?
A)autotrophs and heterotrophs
B)producers and primary consumers
C)photosynthesizers
D)autotrophs
E)green plants

Accepted Answer

Autotrophs, or organisms that can produce their own food through photosynthesis or chemosynthesis, are always necessary in an ecosystem. This is because they provide energy and nutrient sources for all other organisms in the food chain/web. Without autotrophs, there would be no source of energy for heterotrophs to consume, and the ecosystem would collapse. In contrast, while heterotrophs and secondary/tertiary consumers are important in many ecosystems, they are not always necessary for basic energy flow. Similarly, while photosynthesizers and green plants are important autotrophs, they are not required in all ecosystems (e.g. chemosynthetic ecosystems near hydrothermal vents).

Question 15

If photosynthesizing green algae are provided with CO₂ synthesized with heavy oxygen (¹⁸O), later analysis will show that all but one of the following compounds produced by the algae contain the ¹⁸O label. That one is
A)PGA.
B)PGAL.
C)glucose.
D)RuBP.
E)O₂.

Accepted Answer

During photosynthesis, the oxygen released as a byproduct comes from the splitting of water molecules, not from CO₂. Therefore, the O₂ produced will not contain the heavy oxygen label from the CO₂.

Question 16

Figure 10.1 
-Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be
A)to determine if they have thylakoids in the chloroplasts.
B)to test for liberation of O₂ in the light.
C)to test for CO₂ fixation in the dark.
D)to do experiments to generate an action spectrum.
E)to test for production of either sucrose or starch.

Accepted Answer

The liberation of O₂ in the light occurs as a result of photosystem II activity during photosynthesis. If an organism lacks photosystem II, it will not be able to produce oxygen in the light. This is a clear indicator of the absence of photosystem II, making it the best choice for detecting its presence or absence in photosynthetic organisms.

Question 17

Figure 10.1 
-The reaction-center chlorophyll of photosystem I is known as P700 because
A)there are 700 chlorophyll molecules in the center.
B)this pigment is best at absorbing light with a wavelength of 700 nm.
C)there are 700 photosystem I components to each chloroplast.
D)it absorbs 700 photons per microsecond.
E)the plastoquinone reflects light with a wavelength of 700 nm.

Accepted Answer

The reaction-center chlorophyll of photosystem I is known as P700 because it is best at absorbing light with a wavelength of 700 nm. This is the most common explanation given for the naming of P700.

Question 18

Figure 10.1 
-Which of the events listed below occur in the light reactions of photosynthesis?
A)NADP is produced.
B)NADPᴴ is reduced to NADP⁺.
C)carbon dioxide is incorporated into PGA.
D)ATP is phosphorylated to yield ADP.
E)light is absorbed and funneled to reaction-center chlorophyll a.

Accepted Answer

The event of "light being absorbed and funneled to reaction-center chlorophyll a" occur in the light reactions of photosynthesis. This is the primary process by which light energy is converted into chemical energy in the form of ATP and NADPH. The other options listed are events that occur in the Calvin cycle, the second stage of photosynthesis.

Question 19

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
A)CO₂ and glucose
B)H₂O and O₂
C)ADP, Pi, and NADP⁺
D)electrons and H⁺
E)ATP and NADPH

Accepted Answer

The products of the light reactions, ATP and NADPH, are the energy and reducing power used in the Calvin cycle to convert CO₂ into glucose. Choice A, CO₂ and glucose, is incorrect because CO₂ is a reactant utilized in the Calvin cycle, not a product of the light reactions. Choices B and D, H₂O/O₂ and electrons/H⁺ are reactants and intermediates in the light reactions, respectively, and are not directly utilized in the Calvin cycle. Choice C, ADP, Pi, and NADP⁺, are present at the beginning of the light reactions as energy and electron carriers, but are not products of the light reactions that are utilized in the Calvin cycle.

Question 20

In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?
A)chloroplast membranes
B)nuclear membranes
C)free in the cytosol
D)along the outer edge of the nucleoid
E)along the inner surface of the plasma membrane

Accepted Answer

Enzymes that carry out organic synthesis in autotrophic bacteria are located along the inner surface of the plasma membrane. This membrane serves as the site for energy production and enzymatic reactions involved in metabolic processes, including organic synthesis. Chloroplast membranes and nuclear membranes are not present in bacteria, and enzymes are not typically free in the cytosol or along the outer edge of the nucleoid.

Quiz 10: Photosynthesis

Figure 10.1 -Which of the following are directly associated with photosystem I?

Figure 10.1 -In the thylakoid membranes, what is the main role of the antenna pigment molecules?

When oxygen is released as a result of photosynthesis, it is a by-product of which of the following?

What are the products of the light reactions that are subsequently used by the Calvin cycle?

Figure 10.1 -Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?

A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?

Figure 10.1 -Which statement describes the functioning of photosystem II?

Figure 10.1 -What wavelength of light in the figure is most effective in driving photosynthesis?

Where does the Calvin cycle take place?

Figure 10.1 -Compared with the lines for chlorophyll a in the figure, where would you expect to find the lines to differ for chlorophyll b?

In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?

If photosynthesizing green algae are provided with CO₂ synthesized with heavy oxygen (¹⁸O) , later analysis will show that all but one of the following compounds produced by the algae contain the ¹⁸O label. That one is

Figure 10.1 -Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be

Figure 10.1 -The reaction-center chlorophyll of photosystem I is known as P700 because

Figure 10.1 -Which of the events listed below occur in the light reactions of photosynthesis?

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?