Photosynthesis is important because:
I: It is the primary source of all food on earth.
II: It is responsible for the release of oxygen into the atmosphere by green plants.
 
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
Subtopic:  Factors Affecting Photosynthesis |
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The hypothesis “Plants restore to the air whatever breathing animals and burning candles remove” was given, after his experiments, by:
1. Joseph Priestley 2. Jan Ingenhousz
3. Julius von Sachs 4. C. B. Van Neil
Subtopic:  Historical View: Experiments |
 92%
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Who first showed that it is only the green parts of the plants that could release oxygen during photosynthesis?
1. Joseph Priestley 2. Jan Ingenhousz
3. Julius von Sachs 4. C. B. Van Neil
Subtopic:  Historical View: Experiments |
 74%
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Julius von Sachs provided evidence for:
I: production of glucose when plants grow
II: location of green substance in plants in special bodies
Which of the following will be true in light of the information given above?
A: Glucose produced during photosynthesis is usually stored as cellulose in plants.
B: The ‘green substance’ refers to chlorophyll.
C: ‘Special bodies’ refer to chloroplasts in the plant cells.
 
1. Only A and B 2. Only B and C
3. Only A 4. A, B and C
Subtopic:  Historical View: Experiments |
 79%
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Consider the given two statements:
Statement I: Water molecules appear on both side of the equation for photosynthesis in higher plants.
Statement II: The water molecules that enter the reaction are not the same molecules that emerge from the reaction.
 
1. Both Statement I and Statement II are correct and Statement II  explains Statement I
2. Both Statement I  and Statement II  are correct but Statement II  does not explain Statement I
3. Statement I is correct and Statement II is incorrect
4. Both Statement I  and Statement II  are incorrect
Subtopic:  Introduction |

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Joseph Priestley (1733-1804) in 1770 performed a series of experiments that revealed the essential role of air in the growth of green plants. Priestley observed that a candle burning in a closed space – a bell jar, soon gets extinguished (Figure a, b, c, d). Similarly, a mouse would soon suffocate in a closed space. He concluded that a burning candle or an animal that breathe the air, both somehow, damage the air. But when he placed a mint plant in the same bell jar, he found that the mouse stayed alive and the candle continued to burn.

The conclusions that can be drawn from these experiments will be:
I: Plants restore to the air whatever breathing animals and burning candles remove.
II: Sunlight is essential to the plant process that somehow purifies the air fouled by burning candles or breathing animals.
 
1. Only I 2. Only II
3. Both I and II 4. Neither I nor II
Subtopic:  Historical View: Experiments |
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The diagram shows the famous Engelmann experiment that helped us understand important aspects of the process of photosynthesis. What conclusion can be drawn by the pattern of accumulation of aerobic bacteria shown in the diagram?
 

1. Excess carbon dioxide is released by the alga in the area of accumulation.
2. Only red and violet lights are effective for photosynthesis.
3. In the areas of accumulation, most oxygen was liberated by the alga.
4. Bacteria are attracted to red and blue light.
Subtopic:  Pigments |
 56%

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C. B. van Niel proved that:

1. Plants produce glucose when they grow.
2. Blue and red light are effective for photosynthesis.
3. It is only the green parts of the plants that could release oxygen.
4. Hydrogen from a suitable oxidizable compound reduces carbon dioxide to carbohydrates.
Subtopic:  Historical View: Experiments |
 68%
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The correct and complete equation for the process of photosynthesis in higher plants will be:
1. 6CO2 + 12H2O + light energy → C6H12O6 + 6O2+ 6H2O
2. 6CO2 + 6H2O + light energy → C6H12O6 + 6O2
3. CO2 + H2O + light energy → [CH2O] + O2
4. C6H12O6 + 6O2 → 6CO2 + 6H2O
Subtopic:  Historical View: Experiments |
 87%
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When do you think the chloroplasts will be aligned with their flat surfaces parallel to the walls of the mesophyll cells?
1. In dark
2. When light intensity is low
3. When light intensity is high
4. They are always aligned parallel to the walls

Subtopic:  Chloroplast Structure |
 55%
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