Question

A scientist grows tomatoes in greenhouses that differ only in the amount of carbon dioxide in the air. He determines the weight of tomatoes produced by plants in each greenhouse, and compares them to each other and to tomatoes grown in air with a natural, unaltered amount of carbon dioxide. Is this a controlled experiment? Why or why not?

Answer 1

This is an controlled experiment because he is only changing the amount of carbon dioxide in the air. Since he is only changing one variable at a time and comparing it to a natural, unaltered tomatoe area, his experiment is controlled.

Step-by-step explanation:

The definition of a controlled experiment is a test where the person conducting the test only changes one variable at a time in order to isolate the results. An experiment where all subjects involved in the experiment are treated exactly the same except for one deviation is an example of a control experiment.

Answer 2

Yes, this is a controlled experiment.

Step-by-step explanation:

The scientist grows tomatoes inside the greenhouse with altered amount of carbon dioxide. So he is changing an important factor required for the healthy growth of plant and increased growth of fruits. So this is a controlled experiment.

But the size of tomatoes depends not only on one factor i.e. Carbon dioxide, but also depends on the other factors like sunlight, amount of water, temperature and the saturation of the photosynthesizing capacity of that particular plant.