SINDA Tuition
Secondary 2 (Exp) / (NA) Prepared by Miss Sathia
Photosynthesis
Name: __________________________________________
Date: ___________________________________________
Study Notes
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Photosynthesis is the chemical process by which plants make food in their leaves in the
presence of sunlight.
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In this process, plants convert light energy into the chemical energy of sugars→ glucose.
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This process consists of a series of chemical reactions that require raw materials such as
carbon dioxide (CO2) and water (H2O) and store chemical energy in the form of
sugar→glucose.
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As glucose is soluble in water, it is converted to starch which is insoluble and stored in the
plants.

Iodine solution is used to test for the presence of starch in leaves to determine if
photosynthesis has taken place in them.

Oxygen (O2) is a byproduct of photosynthesis and is released into the atmosphere.

Light energy from the sun is trapped by a green substance called chlorophyll contained in
the chloroplasts of leaves which drives the reactions.

The following equation summarizes photosynthesis:
Carbon dioxide + Water → Glucose + oxygen
Reactants

1.
2.
3.
4.
Products
Rate of photosynthesis is affected by:
Intensity of light
Carbon dioxide concentration
Water concentration
Chlorophyll concentration
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SINDA Tuition
Secondary 2 (Exp) / (NA) Prepared by Miss Sathia
Multiple choice questions
1. The stomata:
A. Are holes in the leaves created by insects
B. Allow H2O, CO2, and O2 in and out of the leaf
C. Are surrounded by specialized cells called guards
D. B and C
2. Which of the following environmental factors does NOT directly influence the rate of
photosynthesis:
A. Light Intensity
B. Oxygen Concentration
C. Carbon Dioxide Concentration
D. Temperature
3. Photosynthesis is important because:
A. without it there would be no oxygen in the atmosphere
B. without it there would be very little food for animals
C. (a) and (b)
D. none of the above
4. Why is testing a leaf for starch a reliable indication that photosynthesis has taken place?
A. Starch is formed in photosynthesis
B. Starch is formed from glucose, which is formed in photosynthesis
C. Starch is used in photosynthesis
D. Starch is used to make glucose to be used in photosynthesis
5. Which of the following are used in the overall reactions for photosynthesis?
A. Carbon dioxide
B. Water
C. Light
D. All of the above
Structured questions
1. Define photosynthesis.
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SINDA Tuition
Secondary 2 (Exp) / (NA) Prepared by Miss Sathia
2. What materials are required for photosynthesis? What is produced?
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3. Write the overall reaction for photosynthesis.
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4. Where does the energy for the process come from?
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5. Which pigment converts light energy into chemical energy?
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6. Give 4 factors that affect the rate of photosynthesis.
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