<span>Independent variable: Time plants are watered (ex. 8am, 12pm, 4pm, 8pm, 12am)
Dependent variable: growth of the plant
Controlled variable: 1. same type plants, 2. same amount of sunlight, 3. same type of dirt, 4. same type of water, 5. same amount of water (each are self explanatory of how to control)</span>
Pluto is not considered a planet due to all the reasons you stated above
It's because the main photosynthesis component (Chlorophyll) mostly absorbs red and blue portions. It reflects the green portions which is why most plants are green