1.Plants and some other types of
organisms are able to use light energy
from the sun to convert H20 & CO2
into glucose.
2. Organisms such as plants, algae &
some bacteria which make their own
food from light energy, are called
autotrophs.
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Autotrophs
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Photosynthesis occurs within the chloroplasts of plant
cells. The green pigment that captures the sun’s energy
is chlorophyll.
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5
What is the equation for the
chemical reaction of
photosynthesis?
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Photosynthesis Equation
1.Plants take in inorganic compounds
(water, carbon dioxide)
2.In the presence of light energy they will
convert the inorganic compounds to an
organic compound (glucose)
enzymes
6 Water + 6 Carbon dioxide
Glucose + 6 Oxygen
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Regents Practice Question # 1
The diagram below represents a process that occurs
in a structure of a specialized cell?
Which row in the chart correctly identifies the letters in the diagram?
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Regents Practice Question # 2
Scientists studying ocean organisms are
discovering new and unusual species.
Which observation could be used to determine
that an ocean organism carries out autotrophic
nutrition?
(1) Chloroplasts are visible inside the cells.
(2) Digestive organs are visible upon
dissection.
(3) The organism lives close to the surface.
(4) The organism synthesizes enzymes to
digest food
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Regents Practice Question # 2 (Answer)
Scientists studying ocean organisms are
discovering new and unusual species.
Which observation could be used to determine
that an ocean organism carries out autotrophic
nutrition?
(1) Chloroplasts are visible inside the cells.
(2) Digestive organs are visible upon
dissection.
(3) The organism lives close to the surface.
(4) The organism synthesizes enzymes to
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digest food
What happens during photosynthesis?
• Carbon dioxide enters the leaf
through holes called stomata. It is
a tiny opening or pore, found
mostly on the undersurface of a
plant leaf, and used for gas
exchange.
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Stomata and Guard Cells
•They are located on the underside
of the leaves.
•In the presence of sunlight, the
guard cells swell and this causes
the stoma to open up.
•CO2 gas moves into the leaf and
water vapor diffuses from the leaf.
•In dark conditions, the guard cells
do not swell and the stoma remain
closed and photosynthesis does
not take place.
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What happens during photosynthesis?
• Water is brought up through the roots
to the leaves
• Some of the Glucose is used right
away by the plant for energy; some is
stored as starch; and some is built
into plant tissue.
• Oxygen is released into the
environment.
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Factors Influencing Photosynthesis
1.Temperature
It should be between 0° – 35° C due to
the need for enzyme activity.
2.Light Intensity
Some plants need more light.
3.Water Availability
Some plants need more water.
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Regents Practice Question #3
In some land plants, guard cells are found only on the lower
surfaces of the leaves. In some water plants, guard cells are
found only on the upper surfaces of the leaves.
Explain how guard cells in both land and water plants help
maintain homeostasis. In your answer be sure to:
• identify one function regulated by the guard cells in leaves [1]
• explain how guard cells carry out this function [1]
• give one possible evolutionary advantage of the position of the
guard cells on the leaves of land plants [1]
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Regents Practice Question #3 (Answers)
•Control the entrance of gases into and out of the
leaves of the plant.
•Depending on the amount of light present, the
guard cells will swell or contract causing the
stomata to either open or close.
•If the guard cells were located on top of the
leaves they would remain open most of the time
and the plant might dehydrate because the water
vapor would constantly be leaving the plant.
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Regents Practice Question #4
A student performed an experiment to demonstrate that a plant needs
chlorophyll for photosynthesis. He used plants that had green leaves
with white areas. After exposing the plants to sunlight, he removed a
leaf from each plant and processed the leaves to remove the
chlorophyll. He then tested each leaf for the presence of starch. Starch
was found in the area of the leaf that was green, and no starch was
found in the area of the leaf that was white. He concluded that
chlorophyll is necessary for photosynthesis.
Which statement represents an assumption the student had to
make in order to draw this conclusion?
(1) Starch is synthesized from the glucose produced in the green areas
of the leaf.
(2) Starch is converted to chlorophyll in the green areas of the leaf.
(3) The white areas of the leaf do not have cells.
(4) The green areas of the leaf are heterotrophic
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Regents Practice Question #4
A student performed an experiment to demonstrate that a plant needs
chlorophyll for photosynthesis. He used plants that had green leaves
with white areas. After exposing the plants to sunlight, he removed a
leaf from each plant and processed the leaves to remove the
chlorophyll. He then tested each leaf for the presence of starch. Starch
was found in the area of the leaf that was green, and no starch was
found in the area of the leaf that was white. He concluded that
chlorophyll is necessary for photosynthesis.
Which statement represents an assumption the student had to
make in order to draw this conclusion?
(1) Starch is synthesized from the glucose produced in the green
areas of the leaf.
(2) Starch is converted to chlorophyll in the green areas of the leaf.
(3) The white areas of the leaf do not have cells.
(4) The green areas of the leaf are heterotrophic
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Regents Practice Question 5 & 6
A small water plant (elodea) was placed in bright sunlight for five hours as indicated
below. Bubbles of oxygen gas were observed being released from the plant.
Since oxygen gas is being released, it can be inferred that the plant is
(1) producing glucose
(2) making protein
(3) releasing energy from water
(4) carrying on active transport
What substance did the plant most likely absorb from the water for the process that
produces the oxygen gas?
(1) dissolved nitrogen
(2) carbon dioxide
(3) an enzyme
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(4) a hormone
Regents Practice Question 5 & 6
(Answer)
A small water plant (elodea) was placed in bright sunlight for five hours as indicated
below. Bubbles of oxygen gas were observed being released from the plant.
Since oxygen gas is being released, it can be inferred that the plant is
(1) producing glucose
(2) making protein
(3) releasing energy from water
(4) carrying on active transport
What substance did the plant most likely absorb from the water for the process that
produces the oxygen gas?
(1) dissolved nitrogen
(2) carbon dioxide
(3) an enzyme
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(4) a hormone
Regents Practice Question #7
For the process of autotrophic nutrition, the arrow labeled A
would most likely represent the direction of movement of
(1) carbon dioxide, water, and solar energy
(2) oxygen, glucose, and solar energy
(3) carbon dioxide, oxygen, and heat energy
(4) glucose, water, and heat energy
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Regents Practice Question #7 (Answer)
For the process of autotrophic nutrition, the arrow labeled A
would most likely represent the direction of movement of
(1) carbon dioxide, water, and solar energy
(2) oxygen, glucose, and solar energy
(3) carbon dioxide, oxygen, and heat energy
(4) glucose, water, and heat energy
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Regents Practice Question # 8
Which statement best describes the starch content
of two leaves taken from the same plant shown in the
chart below?
(1) Neither leaf contains starch.
(2) Both leaves contain same
amount of starch.
(3) Leaf A contains more starch
than leaf B.
(4) Leaf B contains more starch
than leaf A.
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Regents Practice Question # 8 (Answer)
Which statement best describes the starch content
of two leaves taken from the same plant shown in the
chart below?
(1) Neither leaf contains starch.
(2) Both leaves contain same
amount of starch.
(3) Leaf A contains more starch
than leaf B.
(4) Leaf B contains more
starch than leaf A.
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What is Cellular Respiration?
• It is a process that is opposite to the process of
photosynthesis.
• Photosynthesis is a process that stores up
energy and cellular respiration is a process that
allows that stored up energy to be released for
use by the cells
• The release of chemical energy for use by cells
is called cellular respiration.
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What is the chemical equation
for cellular respiration?
The chemical equation for Cellular Respiration is:
C6H12O6 + 6O2
6CO2 + 6H2O + ATP Energy
Glucose
Carbon Water
Dioxide
Oxygen
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Comparison of Photosynthesis & Cellular Respiration
Photosynthesis
Cellular Respiration
Function
Energy storage
Energy release
Location
Chloroplasts
Mitochondria
Reactants CO2 and H2O
C6H12O6 and O2
Products
C6H12O6 and O2
CO2 and H2O
Equation
6CO2 + 6H2O
C6H12O6 + 6O2
C6H12O6 + 6O2
6CO2 + 6H2O
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When and where does Cellular Respiration Occur?
•All Eukaryotic cells and most Prokaryotic Cells.
•24 hours a day, 7days a week, 365 days a year
•In other words, it is going on constantly
because cells are alive and have a constant
need for energy.
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What is ATP Energy ?
•A Glucose molecule has too much energy for a cell
to release and use all at one time.
(Think of it as a $100 bill)
•Glucose actually gets broken down into a much
smaller molecule called ATP.
(Think of ATP as a $1 bill)
•One glucose molecule breaks down into about 90
ATP molecules.
•ATP is the chemical fuel that a cell is able to
handle, it is called Adenosine Triphosphate.
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Regents Practice Question # 9
The diagram below represents a plant cell.
Which process takes place in
structure A?
(1) cellular respiration
(2) heterotrophic nutrition
(3) digestion of fats
(4) protein synthesis
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Regents Practice Question # 9 (Answer)
The diagram below represents a plant cell.
Which process takes place in
structure A?
(1) cellular respiration
(2) heterotrophic nutrition
(3) digestion of fats
(4) protein synthesis
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Regents Practice Question # 10
Much of the carbon dioxide produced by
green plants is not excreted as a metabolic
waste because it
(1) can be used for photosynthesis
(2) is too large to pass through cell
membranes
(3) is needed for cellular respiration
(4) can be used for the synthesis of proteins
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Regents Practice Question # 10 (Answer)
Much of the carbon dioxide produced by green
plants is not excreted as a metabolic waste
because it
(1) can be used for photosynthesis
(2) is too large to pass through cell membranes
(3) is needed for cellular respiration
(4) can be used for the synthesis of proteins
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Regents Practice Question # 11
The diagram below represents a biochemical process.
Which molecule is represented by X?
(1) DNA
(2) protein
(3) starch
(4) ATP
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Regents Practice Question #11(Answer)
The diagram below represents a biochemical process.
Which molecule is represented by X?
(1) DNA
(2) protein
(3) starch
(4) ATP
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Regents Practice Question # 12
In what way are photosynthesis and cellular
respiration similar?
(1) They both occur in chloroplasts.
(2) They both require sunlight.
(3) They both involve organic and inorganic
molecules.
(4) They both require oxygen and produce
carbon dioxide
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Regents Practice Question # 12 (Answer)
In what way are photosynthesis and cellular
respiration similar?
(1) They both occur in chloroplasts.
(2) They both require sunlight.
(3) They both involve organic and inorganic
molecules.
(4) They both require oxygen and produce
carbon dioxide
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Regents Practice Question # 13
. The diagram below represents a cell found in some complex organisms. The enlarged
section represents an organelle, labeled X, found in this cell.
Describe the function of organelle X and explain how it is important to the
survival of the cell. In your answer, be sure to:
• identify organelle X [1]
• state the process that this organelle performs [1]
• identify the two raw materials that are needed for this process to occur [1]
• identify one molecule produced by this organelle and explain why it is important to
the organism [2]
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Regents Practice Question # 13 (Answer)
•Organelle x is the mitochondria
•It is the site for cellular respiration to take place.
•Glucose and Oxygen are the raw materials.
•ATP is a molecule that is produced from cellular
respiration. It is important because it is the fuel
for the cell.
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