4:
Independent Variable: Photosynthesis
Dependent Variable: Starch
Starch is a product of photosynthesis. Without photosynthesis, starch cannot form. Therefore starch is dependent on photosynthesis.
5:
Independent Variable: Temperature
Dependent Variable: Animal Metabolism
Animal metabolism will only be affected if the temperature of the room changes. Therefore animal metabolism is dependent on temperature.
9:
Independent Variable: Rainfall
Dependent Variable: Thickness of growth rings
The thickness of the tree's growth rings are determined by the amount of rainfall. Therefore the thickness of growth rings are dependent on rainfall.