Identify the independent variable in this research question: At which concentration of polyacrylamide gel do blood proteins separate the best when performing gel electrophoresis?

Identify the dependent variable in this research question: What effect does temperature have on the rate of sugar (sucrose) crystal formation in saturated sugar solutions?

Identify the independent variable in this research question: What is the relationship of the number of turns of 20-gauge copper wire to magnetic field strength in a simple electromagnet?

Identify the condition in this research question: Which metal serves as the best electrode for producing hydrogen in an electrolysis device at standard temperature and pressure?

Identify the independent variable in this research question: What is the effect of the type of organic compost to the productivity rate of Solanum lycopersicum in a hydroponic set-up?

On the given situation, identify the subject. 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.

On the given situation, identify the dependent variable. Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. Height of the tree is measured once a week.

On the given situation, identify the independent variable. One tank of gold fish is fed the normal amount of food once a day, a second tank is fed twice a day, and a third tank four times a day during a six week study. The fish’s weight is recorded daily.

Identify the subject in this research question: How does the photosynthetic rate of pondweed (Elodea canadensis) vary with light intensity at 30°C?

Identify the condition in this research question: Which antibiotic is most effective in killing Staphylococcus growth in agar plates kept at 37°C?