1. What is the problem or question to be solved?
The question being solved is to find the rate of photosynthesis at different light intensity. We are determining whether light intensity affects photosynthesis.
2. How was the problem solved?
a. What is the hypothesis that was tested?
The rate of photosynthesis is high in high light intensity (Bright light) and low in dark or low light intensity.
b. What are the variables that were used?
Light intensity (Dark and bright light intensity)
The number of bubbles produced in bright (high) light intensity and dull (low) light intensity.
3. Based on your answer to the previous questions, how was the hypothesis tested?
Two leafy branches are cut from a tree and put into transparent tubes, which is filled with water. The tubes, together with the leafy branches are put in a beaker half-full with water, placed upside down. One of the beakers is put on bright sunlight while the other one is closed in a dull place. The rate of photosynthesis is measured by counting the number of bubbles produced in each case. The bubbles produced is oxygen gas produced during photosynthesis.
4. What can you conclude based on the results?
The rate of photosynthesis is high in high light intensity (bright place) and low in low light intensity (dark place). More oxygen bubbles were produced in the bright light intensity than in the dark place (low light intensity). Photosynthesis is a light dependent process. The light-dependent reactions convert energy from the sun into a form that the chloroplast can then use to make sugar from carbon dioxide, in the process producing oxygen as a waste product.
.5. Based on the experimental result, what biases or error sources exist in the process?
• Cutting the leafy stem the wrong way, hence affecting the intake of water by the stem
• Using a plant that had already died, hence not able to absorb water or the chloroplast are already dead
• Mistakes in counting the number of bubbles produced in each case. Missing to count some bubbles
• Using contaminated water