UA BSC 108 Exam 2 QUESTIONS AND ANSWERS
(2025)
What is a photosynthetic autotroph? - CORRECT ANSWER An
organism that makes its own food from inorganic ingredients.
What is the fluid inside chloroplasts called? - CORRECT ANSWER
Stroma
What are the membranes inside chloroplasts called? - CORRECT
ANSWER inner and outer membranes
Write the overall equation for photosynthesis. - CORRECT ANSWER
6CO2+6H2O→C6H12O6+6O2
What is the primary function of pigments in photosynthesis? Name the
primary pigment used in photosynthesis. - CORRECT ANSWER
Pigments absorb certain wavelengths. They are the means by which
the energy of sunlight is captured for photosynthesis. The primary
pigment used in photosynthesis is Chlorophylla-a.
Why are leaves green? - CORRECT ANSWER Their green color is
from chlorophyll, a pigment (light- absorbing molecule) in the
chloroplasts that plays a central role in converting solar energy to
chemical energy.
How and where does water enter a plant? - CORRECT ANSWER
Water enters root hair cells by osmosis.
How and where does carbon dioxide enter a plant? - CORRECT
ANSWER Carbon Dioxide diffuses through small holes in the
underside of leaves, called the stomata.
The light reactions take place in three stages. Name the stages and
summarize the events of each stage. 1. Photons excite electrons in
,the chlorophyll of the first photosystem. These photons are then
trapped by the primary electron acceptor. This photosystem then
replaces the lost electrons by extracting new ones from water. This is
the step that releases O2 during photosynthesis. 2. Energized
electrons from the first photosystem pass down an electron transport
chain to the second photosystem. The chloroplast uses the energy
released by this electron "fall" to make ATP. 3. The second
photosystem transfers its light-excited electrons to NADP+, reducing it
to NADPH.
List all products of the light reactions. carbon dioxide, water. Glucose,
oxygen
The Calvin cycle has three main stages. Name the stages and
summarize the events of each stage. - CORRECT ANSWER "1)
Carbon Fixation- The enzyme rubisco combines CO2 with 5-carbon
sugar rubulose biphosphate (RuBP). The unstable product formed
splits into 2 molecules of 3-carbon 3-phosphoglyceric acid (3-PGA).
2) Reduction- Energy from 6 molecules of ATP is used to oxidize
NADPH to NADP+. Six molecules of 3-PGA are reduced, producing six
molecules of energy-rich 3-carbon sugar G3P.
3) Release of one molecule of G3P- Five of the previously created G3Ps
remain in the cycle, but one molecule is released.
4) Regeneration of RuBP - series of chemical reactions uses energy
from ATP to rearrange the atoms of the 5 G3P molecules, (15 total
carbons), which forms 3 RuBP molecules (15 total carbons).
These will start another turn of the cycle.
"
List all products in the Calvin cycle. - CORRECT ANSWER "6
Turns of the Calvin Cycle→ 1 C₆H₁₂O₆
6CO₂ → 1 C₆H₁₂O₆
18 ATP + 12 NADPH → 1 C₆H₁₂O₆
Left over ATP is used elsewhere by the cell. "
Give two examples of plants that use C4 photosynthesis. - CORRECT
ANSWER "1) Corn
2) Sugarcane"
, What environmental factor is C4 photosynthesis an adaptation for? -
CORRECT ANSWER High levels of CO2 and drought environments
Contrast carbon fixation in C4 and CAM plants. C4 plants initially
attach CO2toPEP to form the four-carbon compound OAA using the
enzyme PEP carboxylase. This takes place in the loosely packed cells
called mesophyll cells. OAA is then pumped to another set of cells, the
bundle sheath cells, which surround the leaf vein. There, it releases
the CO2for use by Rubisco. By concentrating CO2in the bundle sheath
cells, C4plants promote the efficient operation of the Calvin-Benson
cycle and minimize photorespiration. CAM plants also initially attach
CO2to PEP and form OAA. However, instead of fixing carbon during the
day and pumping the OAA to other cells, CAM plants fix carbon at
night and store the OAA in large vacuoles within the cell. This allows
them to have their stomates open in the cool of the evening, avoiding
water loss, and to use the CO2 for the Calvin-Benson cycle during the
day, when it can be driven by the sun's energy.
1. How does asexual reproduction differ from sexual reproduction? -
CORRECT ANSWER Asexual Reproduction involves one parent
and produces offspring that are genetically identical to each other and
to the parent. Sexual Reproduction involves two parents and produces
offspring that are genetically unique.
2. What are the two main phases of the eukaryotic cell cycle? -
CORRECT ANSWER "a. Interphase
b. Mitotic phase"
3. During which phase of the cell cycle does DNA duplicate? -
CORRECT ANSWER interphase- chromosome duplication
4. What is the function of mitosis? - CORRECT ANSWER in mitosis
the nucleus and its contents, most importantly, the divided
chromosomes, divide and are evenly distributed, forming two
daughter, nuclei
(2025)
What is a photosynthetic autotroph? - CORRECT ANSWER An
organism that makes its own food from inorganic ingredients.
What is the fluid inside chloroplasts called? - CORRECT ANSWER
Stroma
What are the membranes inside chloroplasts called? - CORRECT
ANSWER inner and outer membranes
Write the overall equation for photosynthesis. - CORRECT ANSWER
6CO2+6H2O→C6H12O6+6O2
What is the primary function of pigments in photosynthesis? Name the
primary pigment used in photosynthesis. - CORRECT ANSWER
Pigments absorb certain wavelengths. They are the means by which
the energy of sunlight is captured for photosynthesis. The primary
pigment used in photosynthesis is Chlorophylla-a.
Why are leaves green? - CORRECT ANSWER Their green color is
from chlorophyll, a pigment (light- absorbing molecule) in the
chloroplasts that plays a central role in converting solar energy to
chemical energy.
How and where does water enter a plant? - CORRECT ANSWER
Water enters root hair cells by osmosis.
How and where does carbon dioxide enter a plant? - CORRECT
ANSWER Carbon Dioxide diffuses through small holes in the
underside of leaves, called the stomata.
The light reactions take place in three stages. Name the stages and
summarize the events of each stage. 1. Photons excite electrons in
,the chlorophyll of the first photosystem. These photons are then
trapped by the primary electron acceptor. This photosystem then
replaces the lost electrons by extracting new ones from water. This is
the step that releases O2 during photosynthesis. 2. Energized
electrons from the first photosystem pass down an electron transport
chain to the second photosystem. The chloroplast uses the energy
released by this electron "fall" to make ATP. 3. The second
photosystem transfers its light-excited electrons to NADP+, reducing it
to NADPH.
List all products of the light reactions. carbon dioxide, water. Glucose,
oxygen
The Calvin cycle has three main stages. Name the stages and
summarize the events of each stage. - CORRECT ANSWER "1)
Carbon Fixation- The enzyme rubisco combines CO2 with 5-carbon
sugar rubulose biphosphate (RuBP). The unstable product formed
splits into 2 molecules of 3-carbon 3-phosphoglyceric acid (3-PGA).
2) Reduction- Energy from 6 molecules of ATP is used to oxidize
NADPH to NADP+. Six molecules of 3-PGA are reduced, producing six
molecules of energy-rich 3-carbon sugar G3P.
3) Release of one molecule of G3P- Five of the previously created G3Ps
remain in the cycle, but one molecule is released.
4) Regeneration of RuBP - series of chemical reactions uses energy
from ATP to rearrange the atoms of the 5 G3P molecules, (15 total
carbons), which forms 3 RuBP molecules (15 total carbons).
These will start another turn of the cycle.
"
List all products in the Calvin cycle. - CORRECT ANSWER "6
Turns of the Calvin Cycle→ 1 C₆H₁₂O₆
6CO₂ → 1 C₆H₁₂O₆
18 ATP + 12 NADPH → 1 C₆H₁₂O₆
Left over ATP is used elsewhere by the cell. "
Give two examples of plants that use C4 photosynthesis. - CORRECT
ANSWER "1) Corn
2) Sugarcane"
, What environmental factor is C4 photosynthesis an adaptation for? -
CORRECT ANSWER High levels of CO2 and drought environments
Contrast carbon fixation in C4 and CAM plants. C4 plants initially
attach CO2toPEP to form the four-carbon compound OAA using the
enzyme PEP carboxylase. This takes place in the loosely packed cells
called mesophyll cells. OAA is then pumped to another set of cells, the
bundle sheath cells, which surround the leaf vein. There, it releases
the CO2for use by Rubisco. By concentrating CO2in the bundle sheath
cells, C4plants promote the efficient operation of the Calvin-Benson
cycle and minimize photorespiration. CAM plants also initially attach
CO2to PEP and form OAA. However, instead of fixing carbon during the
day and pumping the OAA to other cells, CAM plants fix carbon at
night and store the OAA in large vacuoles within the cell. This allows
them to have their stomates open in the cool of the evening, avoiding
water loss, and to use the CO2 for the Calvin-Benson cycle during the
day, when it can be driven by the sun's energy.
1. How does asexual reproduction differ from sexual reproduction? -
CORRECT ANSWER Asexual Reproduction involves one parent
and produces offspring that are genetically identical to each other and
to the parent. Sexual Reproduction involves two parents and produces
offspring that are genetically unique.
2. What are the two main phases of the eukaryotic cell cycle? -
CORRECT ANSWER "a. Interphase
b. Mitotic phase"
3. During which phase of the cell cycle does DNA duplicate? -
CORRECT ANSWER interphase- chromosome duplication
4. What is the function of mitosis? - CORRECT ANSWER in mitosis
the nucleus and its contents, most importantly, the divided
chromosomes, divide and are evenly distributed, forming two
daughter, nuclei
