WorksheetsC3, C4 and CAM photosynthesis
Total questions: 27
Worksheet time: 16mins
Which of the following outputs of the light dependent reactions of photosynthesis are used in the Calvin cycle?
Rubisco is important in which step of photosynthesis
energizing the electrons in chlorophyll in order to activate NAD+
carbon fixation of CO2 during the Calvin cycle
regeneration phase as RUBP is made during the Calvin cycle
reduction of the carbon chain during the Calvin cycle
Photorespiration lowers the efficiency of photosynthesis by
preventing carbon dioxide molecules from being produced
Preventing the fixation of CO2 by Rubisco
Prevents formation of ATP molecules
Prevents oxygen reduction by Rubisco
have higher rates of photorespiration when the temperature increases
can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations.
do not use rubisco for carbon fixation.
grow better under cool, moist conditions.
In C4 plants the initial reactions to fix CO2 occur in the
Guard cells
Epidermal cells
Mesophyll cells
Bundle-sheath cells
Where does the Calvin cycle take place during C3 photosynthesis
Stroma of the chloroplasts of mesophyll cells
thylakoid membrane of chloroplast in the mesophyll cells
Thylakoid membranes of chloroplasts in the Bundle sheath cells
Stroma of chloroplasts in guard cells
fix CO2 into organic acids (e.g. malate) and store it in vacuoles during the night when stomata are open due to cool temperatures.
fix CO2 into by combining it with RuBP in the Calvin cycle during the night time.
obtain CO2 through their roots during the day and convert it into malate to be transported by xylem to the leaves.
fix CO2 into organic acids in the mesophyll cells and then transport it to bundle sheath cells for the Calvin cycle.
Why are C4 plants able to carry out photosynthesis efficiently?
They do not use the Calvin cycle during photosynthesis
They use enzymes (PEP carboxylase) to fix carbon dioxide into malate before entering the Calvin cycle
They are adapted to cold climates and absorb CO2 efficiently throughout the day
They conserve water efficiently and have a higher rate of photosynthesis than other plants.
Which of the following does NOT occur during the Calvin Cycle
carbon fixation
oxidation of NADPH
release of oxygen
regeneration of the carbon dioxide acceptor
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.
Photorespiration involves
the production of oxygen gas during the break down of sugar
the breakdown of sugar when CO2 levels are low.
the production of massive amounts of ATP in the thylakoid
water being pulled out of the plant
Why does photorespiration occur?
stomata are closed (to prevent transpiration) and the ratio of CO2 levels compared to O2 is too low
stomata are closed and O2 levels are too low.
stomata are open and too much water is leaving the plant by the process of transpiration
stomata are open and the plant receives too much CO2
The process of photosynthesis in C4 plants involves
Physically separating carbon fixation and the Calvin cycle in different cells
Converting carbon dioxide into organic acids at night time to be used during the day
Photorespiration occurring when Oxygen levels are high
The light dependent reaction not occurring
The process of photosynthesis in CAM plants involves
Physically separating carbon fixation and the Calvin cycle in different cells
Converting carbon dioxide into organic acids at night time to be used during the day
Photorespiration occurring when Oxygen levels are high
The light dependent reaction not occurring
Which type of plant does not have a carbon dioxide storage method
C3
C4
CAM
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.
In C4 plants, the Calvin cycle occurs in
Guard cells
Epidermal cells
Mesophyll cells
Bundle-sheath cells
The main advantage of CAM Photosynthesis is the ability to avoid (there may be more than one correct answer):
Transpiration
Photorespiration
Carbon fixation
Carbon reduction
Malate or other organic acids
All forms of photosynthesis involve the enzyme RuBisCo in the Calvin cycle.
True
False
As the intensity of light increases, the rate of photosynthesis in a C3 plant will...
steadily increase
increase exponentially
increase, then level off, then decrease
decrease at first, then increase
The process of photosynthesis in CAM plants has a disadvantage which is
Plant entering photorespiration when temperature increases
A low overall rate of photosynthesis (leading to a slow growth rate) due to limited storage of malate
Photorespiration when Oxygen levels are high
The light dependent and independent reactions occurring in Bundle sheath cells requiring energy expenditure
The plant that would have the highest rate of photosynthesis in high humidity is
C3
C4
CAM
The plants that have adaptations to a temperate environment are
C3 plants
C4 plants
CAM plants
