NEW
Font size
WorksheetsPhotosynthesis Level 2
Total questions: 15
Worksheet time: 8mins
If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), later analysis will show that all of the following molecules produced by the algae contain 18O except
glyceraldehyde 3-phosphate (G3P)
glucose
ribulose bisphosphate (RuBP)
O2
As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from?
photosystem I
photosystem II
cyclic electron flow
non-cyclic electron flow
Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution. What would be likely to happen?
The isolated chloroplasts will make ATP
The Calvin cycle will be activated
The isolated chloroplasts will generate oxygen gas
The isolated chloroplasts will reduce NADP+ to NADPH
A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.
The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark.
The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.
The dissolved oxygen in the flask with algae will always be higher.
The dissolved oxygen in the flask with algae will always be lower.
The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find?
The pH within the thylakoid is less than that of the stroma.
The pH of the stroma is lower than that of the other two measurements.
The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol.
The pH of the thylakoid space is higher than that anywhere else in the cell.
What would be the expected effect on plants if the atmospheric CO2 concentration was doubled?
All plants will experience increased rates of photosynthesis.
C3 plants will have faster growth; C4 plants will be minimally affected.
C4 plants will have faster growth; C3 plants will be minimally affected.
C3 plants will have faster growth; C4 plants will have slower growth.
Why are C4 plants able to photosynthesize with no apparent photorespiration?
They do not participate in the Calvin cycle.
They use PEP carboxylase to initially fix CO2.
They conserve water more efficiently.
They exclude oxygen from their tissues.
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
fix CO2 into organic acids during the night.
fix CO2 into sugars in the bundle-sheath cells.
fix CO2 into pyruvate in the mesophyll cells.
use photosystem I and photosystem II at night.
The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?
C4 compromises on water loss and CAM compromises on photorespiration.
Both minimize photorespiration but expend more ATP during carbon fixation.
CAM plants allow more water loss, whereas C4 plants allow less CO2 into the plant.
C4 plants allow less water loss but CAM plants allow more water loss.
If the carbon atom of each of the incoming CO2 molecules is labeled with a radioactive isotope of carbon, which organic molecules will be radioactively labeled after one cycle?
C only
B, C, D and E
C, D and E
B and C only
To identify the molecule that accepts CO2, Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO2 or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO2 acceptor? Study Figure 8.2 to help you in determining the correct answer.
The CO2 acceptor concentration would decrease when either the CO2 or light is cut off.
The CO2 acceptor concentration would increase when either the CO2 or light is cut off.
The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off.
The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off.
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?
Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
Bacteria congregated in these areas because these areas had the most oxygen being released.
Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.
Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.
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 (mentioned above) without passing light through a prism, what would you predict?
The bacteria would be relatively evenly distributed along the algal filaments.
The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
The number of bacteria would decrease due to a decrease in the temperature of the water.
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed.
What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure?
full-spectrum white light
green light
a mixture of blue and red light
yellow light
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed.
A gardener is concerned that her greenhouse is getting too hot from too much light, and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy, but still maximize plant growth?
green
blue
yellow
orange
