Q . Devise an activity to show that CO2 is essential for photosynthesis.
Answers
The following activity proves that CO2 is essential for photosynthesis.
Activity:
1. Two potted plants of same species and of approximately of same size are taken . They are placed in a safe dark place for three days.
2. Each potted plant is placed on separate glass plates and a watch-glass/petridish containing KOH (potassium hydroxide solution) is kept by the side of one of the plants. The potassium hydroxide solution is used to absorb carbon dioxide.
3. Separate bell-jars are placed to cover both plants . The set-up is made air tight by applying vaseline to seal the bottom of the jars to the glass plates.
4. The plants are then placed in sunlight for 2–3 days.
5. After 2–3 hours, a leaf is plucked from each plant and boiledin water and then in alcohol separately to decolourize them.
6. Each decolourized leaf is placed in separate petridish and iodine solution is poured on each leaf.
7. The leaf of plant of set-up B which did not has potassium hydroxide turned deep blue black showing presence of enough starch. The leaf taken from set-up A either turned slightly blue or remains yellowish showing presence of a little amount of starch or no starch.
This activity proved that CO2 is essential for photosynthesis.
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Devise an activity to show that carbon dioxide is essential for photosynthesis.
The following activity proves that CO2 is essential for photosynthesis.
Activity:
1. Two potted plants of same species and of approximately of same size are taken . They are placed in a safe dark place for three days.
2. Each potted plant is placed on separate glass plates and a watch-glass/petridish containing KOH (potassium hydroxide solution) is kept by the side of one of the plants. The potassium hydroxide solution is used to absorb carbon dioxide.
3. Separate bell-jars are placed to cover both plants . The set-up is made air tight by applying vaseline to seal the bottom of the jars to the glass plates.
4. The plants are then placed in sunlight for 2–3 days.
5. After 2–3 hours, a leaf is plucked from each plant and boiledin water and then in alcohol separately to decolourize them.
6. Each decolourized leaf is placed in separate petridish and iodine solution is poured on each leaf.
7. The leaf of plant of set-up B which did not has potassium hydroxide turned deep blue black showing presence of enough starch. The leaf taken from set-up A either turned slightly blue or remains yellowish showing presence of a little amount of starch or no starch.
This activity proved that CO2 is essential for photosynthesis.