The students see an experiment to learn what plants need to grow.
These seeds received water, but we kept them in a drawer, so they got no sunlight. Therefore, they were not able to conduct photosynthesis properly, so the chlorophyll, which gives plants their green color, never became active. Thus, the blades of grass are yellow.
The seeds on the left did not receive any water, so they did not grow. However, the seeds on the right got water and sunlight, so they grew, and the blades turned green because they were able to conduct photosynthesis properly, activating the chlorophyll.
