Answer:
The correct answer is option D. Light and some other factors are necessary for chlorophyll production
Explanation:
By this experiment, it is clear that light is the major factor that helps in the production of chlorophyll in seedlings or plants. In this study, placing the seeds in the light turns 75 seedlings green which is possible by the production of the green pigment, chlorophyll only. So, it is proved that light is a key factor in the production of chlorophyll.
Besides light, there must be some other factors (mineral nutrition and chemical metabolites) that also play role in the production of chlorophyll or increase or decrease of the chlorophyll production as few seedlings did not turn green in the study.
