Question

Besides temperature, what other independent variables could you alter to test whether radish seed swelling is essentially a physical process or a chemical process?

Short answer

The addition of poison to the water that can affect or block a chemical (metabolic) process in the seed can be used as an independent variable.

Step-by-step solution

Outline of the experiment

To check whether water uptake by seeds is a temperature-dependent process, researchers took radish seeds and soaked them in water maintained at four different temperatures for 30 minutes.

The seeds were then soaked and weighted to determine the percent increase in mass due to water uptake.

Temperature is an independent variable

The temperature was the independent variable in the experiment because four different temperatures were considered to measure radish seeds' water uptake. The physical uptake of water increased the mass of the seeds, which was dependent on temperature.

Another independent variable to confirm water uptake is a physical process

When a metabolic poison is considered an independent variable, a control without the poison is considered for the experiment. The results of the experimental and control group are then compared.

If the seeds absorb water in the presence of the metabolic poison, it confirms that water uptake by seeds is a physical process.