D) Robert Hooke first discovered cells when observing cork under the microscope.
Answer:
The correct answer is oxygen was produced by photosynthesis.
Explanation:
During the process of photosynthesis carbon dioxide is consumed and oxygen is released in presence of sunlight.
when plant is placed in the yellow solution and kept in sunlight the plant undergo photosynthesis.As a result the yellow solution in the tube in presence of sunlight turns blue because oxygen is released by reduction which is responsible for the blue coloration of the solution.
On the other hand the plant that is placed in dark unable to undergo photosynthesis due to which there is no change in color.
