LIFESCI 7A Midterm 2 Exam Questions and Answers Already Passed Latest Update 2025-2026
During photosynthesis, _____ is reduced to _____.
oxygen; water
water; carbon dioxide
carbon dioxide; sugar
sugar; oxygen
carbon dioxide; oxygen - Answers carbon dioxide; sugar
The fluid-filled interior compartment of the thylakoid network is referred to as the:
cytoplasm.
stroma.
grana.
lumen.
intermembrane space. - Answers lumen
In plants and algae, _____ is the source of the electrons needed for photosynthesis.
CO2
H+
H2O
O2
NADPH - Answers H2O
In plants and algae, which of the following is a by-product of photosynthesis?
O2
H+
,carbohydrates
CO2
C6H12O6 - Answers O2
Which of the following is TRUE concerning the Calvin cycle and light-harvesting reactions of
photosynthesis?
They take place in different compartments of the same organelle.
They take place in different types of cells in the plant.
None of the other answer options is correct.
They take place in different organelles. - Answers They take place in different compartments of
the same organelle.
Which of the following does NOT happen in the Calvin cycle of photosynthesis?
reduction of NADP+ to NADPH
the synthesis of a three-carbon carbohydrate
the incorporation of CO2 into an organic molecule by RUBISCO
hydrolysis of ATP to ADP - Answers reduction of NADP+ to NADPH
Which of the following CORRECTLY describes the role of rubisco in the Calvin cycle?
Rubisco uses NADPH to reduce 3-phosphoglycerate to a three-carbon sugar.
Rubisco incorporates CO2 from the atmosphere into an organic molecule.
None of the other answer options is correct.
Rubisco uses ATP to regenerate RUBP. - Answers Rubisco incorporates CO2 from the
atmosphere into an organic molecule.
Which step of the Calvin cycle would be affected first by a lack of NADPH?
regeneration
, carboxylation
All of these choices are correct.
reduction - Answers reduction
In photosynthesis, the reduction of 3-phosphoglycerate to form carbohydrate requires:
RuBP.
NADPH.
ATP and NADPH.
ATP.
rubisco. - Answers ATP and NADPH
Carbon enters the Calvin cycle in the form of:
RuBP.
glucose.
3-PGA.
CO2.
triose phosphates. - Answers CO2
Where are the chlorophyll molecules located in plant cells that carry out photosynthesis?
in the lumen of the thylakoids in the chloroplasts
in the cytoplasm
in the thylakoid membranes
in the stroma of the chloroplasts
in the plasma membrane - Answers in the thylakoid membranes
As electrons flow from one photosystem to another, the amount of energy present in the
electrons decreases. How does the plant cell use the energy lost by the electrons?
During photosynthesis, _____ is reduced to _____.
oxygen; water
water; carbon dioxide
carbon dioxide; sugar
sugar; oxygen
carbon dioxide; oxygen - Answers carbon dioxide; sugar
The fluid-filled interior compartment of the thylakoid network is referred to as the:
cytoplasm.
stroma.
grana.
lumen.
intermembrane space. - Answers lumen
In plants and algae, _____ is the source of the electrons needed for photosynthesis.
CO2
H+
H2O
O2
NADPH - Answers H2O
In plants and algae, which of the following is a by-product of photosynthesis?
O2
H+
,carbohydrates
CO2
C6H12O6 - Answers O2
Which of the following is TRUE concerning the Calvin cycle and light-harvesting reactions of
photosynthesis?
They take place in different compartments of the same organelle.
They take place in different types of cells in the plant.
None of the other answer options is correct.
They take place in different organelles. - Answers They take place in different compartments of
the same organelle.
Which of the following does NOT happen in the Calvin cycle of photosynthesis?
reduction of NADP+ to NADPH
the synthesis of a three-carbon carbohydrate
the incorporation of CO2 into an organic molecule by RUBISCO
hydrolysis of ATP to ADP - Answers reduction of NADP+ to NADPH
Which of the following CORRECTLY describes the role of rubisco in the Calvin cycle?
Rubisco uses NADPH to reduce 3-phosphoglycerate to a three-carbon sugar.
Rubisco incorporates CO2 from the atmosphere into an organic molecule.
None of the other answer options is correct.
Rubisco uses ATP to regenerate RUBP. - Answers Rubisco incorporates CO2 from the
atmosphere into an organic molecule.
Which step of the Calvin cycle would be affected first by a lack of NADPH?
regeneration
, carboxylation
All of these choices are correct.
reduction - Answers reduction
In photosynthesis, the reduction of 3-phosphoglycerate to form carbohydrate requires:
RuBP.
NADPH.
ATP and NADPH.
ATP.
rubisco. - Answers ATP and NADPH
Carbon enters the Calvin cycle in the form of:
RuBP.
glucose.
3-PGA.
CO2.
triose phosphates. - Answers CO2
Where are the chlorophyll molecules located in plant cells that carry out photosynthesis?
in the lumen of the thylakoids in the chloroplasts
in the cytoplasm
in the thylakoid membranes
in the stroma of the chloroplasts
in the plasma membrane - Answers in the thylakoid membranes
As electrons flow from one photosystem to another, the amount of energy present in the
electrons decreases. How does the plant cell use the energy lost by the electrons?
