Science Common Sense


1223 - What factors, such as sunlight, carbon dioxide, and water, affect photosynthesis and how can their effects be verified through experiments

Photosynthesis is how plants make food from sunlight. Here's how some factors affect photosynthesis, and how we can test them with experiments:

  1. Sunlight: More sunlight means more photosynthesis. You can test this by placing identical plants in:
  2. Bright light (direct sunlight)
  3. Medium light (shaded area)
  4. Low light (basement or dark room) Compare the growth after a few weeks.

  5. Carbon Dioxide: More CO2 means more photosynthesis. Test by placing identical plants in:

  6. A sealed container with normal air
  7. A sealed container with high CO2 concentration
  8. A sealed container with low CO2 concentration Compare the growth after a few weeks.

  9. Water: Enough water is necessary for photosynthesis. Test by watering identical plants:

  10. Normally (every other day)
  11. More (every day)
  12. Less (once a week) Compare the growth after a few weeks.

  13. Temperature: Ideal temperature for photosynthesis varies among plants. Test by placing identical plants in:

  14. Hot (warm greenhouse)
  15. Medium (average room temperature)
  16. Cool (basement or shaded area) Compare the growth after a few weeks.

Here's how you can verify the results: - Take pictures and compare photos of the plants before and after the experiment. - Measure the plants' growth using a ruler. - Use a tool to measure oxygen output (as a proxy for photosynthesis rate).

Step-by-Step Example

Question: How does sunlight affect photosynthesis?

Materials: 3 identical plants, 3 containers, a sunny window, a shaded area, a dark room.

Procedure: Place one plant in direct sunlight, one in a shaded area, and one in a dark room. Water them equally and keep them at the same temperature. Measure and compare their growth after 2 weeks.

Conclusion: Compare the growth of the plants. The one in direct sunlight should grow more, proving that sunlight positively affects photosynthesis.