You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured. i think the indepent variable is sunflower ... variable is height measured and the control variable is the fourth plant.
Cells from the cheek are a type of epithelial cell, similar to skin. ... They can be seen faintly even at 40x (scanning power), but the most dramatic images are at 400x where the nucleus is clearly visible as a dark spot in the center of the cell.
