Photosythesis Flashcards
Plant and Fungi Diversity
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
a) electrons and H+
b) ADP, pi, and NADP+
c) CO2 and glucose
d) ATP and NADPH
e) H2O and O2
d) ATP and NADPH
Reactions that require CO2 take place in
a) the Calvin cycle alone.
b) the light reactions alone.
c) both the light reactions and the Calvin cycle.
d) the chloroplast, but are not part of photosynthesis.
e) neither the light reactions nor the Calvin cycle.
a) The Calvin cycle alone
Why are C4 plants able to photosynthesize with no apparent photorespiration?
They use PEP Carboxylase to initially fix CO2
What wavelength of light is most effective in driving photosynthesis?
a) 730nm (red)
b) 475nm (blue)
c) 625nm (orange)
d) 575nm (green)
e) 420nm (violet)
e) 420nm
When oxygen is released as a result of photosynthesis, it is a direct by-product of
splitting water molecules
Photorespiration occurs when rubisco reacts RuBP with
O2
Compared to C3 plants, C4 plants
a) grow better under cool, moist conditions
b) do not use rubisco
c) have higher rates of photorespiration
d) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria
e) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations
e) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations
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.
If the power fails and the lights go dark, what will happen to CO2 levels?
a) CO2 will fall because plants will increase CO2 fixation
b) CO2 will rise as a result of animal respiration only
c) CO2 will rise as a result of animal and plant respiration
d) CO2 will remain balanced because plants will continue to fix CO2 in the dark
e) CO2 will fall because plants will cease to respire in the dark
C) CO2 will rise as a result of both animal and plant respiration
Plants photosynthesize only in the light. Plants respire
a) only when excessive light energy induces photorespiration
b) in the light only
c) never-they get their ATP from photophosphorylation
d) in the dark only
e) both in light and dark
e) both in light and dark
Where is the Calvin cycle located in a C4 plant?
a) bundle-sheath cells
b) mesophyll cells
c) stomata
d) stems
e) the chloroplasts in leaves
a) bundle-sheath cells
CO2 + H2O → [CH2O] + O2 represents the simplified equation for
a) respiration
b) chemiosmosis
c) photosynthesis
d) photoposphorylation
e) chemisynthesis
c) photosynthesis
In C3 photosynthesis, the reactions that require ATP take place in
a) the light reactions alone
b) the Calvin cycle alone
c) the chloroplast, but are not part of photosynthesis
d) neither the light reactions nor the Calvin cycle
e) both the light reactions and the Calvin cycle
b) the Calvin cycle alone
Where do the enzymatic reactions of the Calvin cycle take place?
a) thylakoid membranes
b) matrix of the mitochondria
c) stroma of the chloroplast
d) thylakoid space
e) cytosol around the chloroplast
c) stroma of the chloroplast
If atmospheric CO2 concentrations increase twofold or more, how will plants be affected, disregarding any changes in climate?
a) C4 plants will have faster growth; C3 plants will be minimally affected.
b) C3 plants will have faster growth; C4 plants will be minimally affected.
c) Plant growth will not be affected because atmospheric CO2 concentrations are never limiting for plant growth.
d) C3 plants will have faster growth; C4 plants will have slower growth.
e) All plants will experience increased rates of photosynthesis.
b) C3 plants will have faster growth; C4 plants will be minimally affected
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
a) use photosystem I and photosystem II at night
b) fix CO2 into organic acids during the night
c) fix CO2 into pyruvate in the mesophyll cells
d) use the enzyme phosphofructokinase, which outcompetes rubisco for CO2
e) fix CO2 into sugars in the bundle-sheath cells
b) fix CO2 into organic acids during the night
What is the primary function of the Calvin cycle?
a) use NADPH to release carbon dioxide
b) synthesize simple sugars from carbon dioxide
c) split water and release oxygen
d) use ATP to release carbon dioxide
e) transport RuBP out of the chloroplast
b) synthesize simple sugars from carbon dioxide
It is a particularly hot, dry summer. The town has banned excessive water use and so you cannot water your lawn. After a few weeks the grass has gone brown, except a few patches where the grass seems to be doing fine. You notice that this grass has a broader leaf and is not the same species as most of your lawn. You conclude that this grass is a
a) C4 plant
b) C3 plant
c) a mutant
d) C5 plant
e) CAM plant
a) C4 plant
Photorespiration lowers the efficiency of photosynthesis by releasing (rather than fixing)
a) RuBP carboxylase molecules
b) ATP molecules
c) ribulose bisphosphate molecules
d) 3-phosphglycerate molecules
e) carbon dioxide molecules
e) carbon dioxide molecules
Where do the enzymatic reactions of the Calvin cycle take place?
a) thylakoid membranes
b) matrix of the mitochondria
c) stroma of the chloroplast
d) thylakoid space
e) cytosol around the chloroplast
c) stroma of the chloroplast
Why are C4 plants able to photosynthesize with no apparent photorespiration?
a)They use PEP carboxylase to initially fix CO2
b) They are adapted to cold, wet climates
c) They exclude oxygen from their tissues
d) They conserve water more efficiently
e) They do not participate in the Calvin cycle
a) They use PEP carboxylase to initially fix CO2
What wavelength of light in the figure is most effective in driving photosynthesis?
a) 730nm
b) 475nm
c) 625nm
d) 575nm
e) 420nm
e) 420nm
CO2 + H2O → [CH2O] + O2 represents the simplified equation for…
a) respiration
b) chemiosmosis
c) photosynthesis
d) photophosphorylation
e) chemisynthesis
c) photosynthesis
If the process of photosynthesis had never evolved on Earth, this planet would..
a) have no land and be primarily ocean
b) have no water and be dry land
c) be very similar to the way it is today
d) have no oxygen and thus no life
e) only contain anaerobic organisms
e) only contain anaerobic organisms
The NADPH required for the Calvin cycle comes from…
a) oxidative phosphorylation
b) reactions initiated in photosystem II
c) reactions initiated in photosystem I
d) the citric acid cycle
e) glycolysis
c) reactions initiated in photosystem I
Photorespiration lowers the efficiency of photosynthesis by releasing (rather than fixing)…
a) RuBP carboxylase molecules
b) ATP molecules
c) ribulose bisphosphate molecules
d) 3-phosphoglycerate molecules
e) carbon dioxide molecules
e) carbon dioxide molecules
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
a) electrons and H+
b) ADP, Pi, NADP +
c) CO2 and glucose
d) ATP and NADPH
e) H2O and O2
ATP and NADPH
Which molecule(s) of the Calvin cycle is (are) also found in glycolysis?
a) B, C, and E only
b) 3-phosphoglycerate only
c) B, C, E, and 3-phosphoglycerate
d) E only
e) B, C, D, and 3-phosphoglycerate only
e) B, C, D, and 3-phosphoglycerate only
In a plant leaf, the reactions that produce NADH occur in
a) both the light reactions and the Calvin cycle
b) neither the light reactions nor the Calvin cycle
c) the Calvin cycle alone
d) the chloroplast, but are not part of photosynthesis
e) the light reactions alone
b) neither the light reactions nor the Calvin cycle
