Stella and John wanted to test for the effects of temperature on the growth of plants. They took 24 plants- 1 was a control at normal room temperature (20 degrees centigrade) and the other 23 were split into these groups: 4-at 21 degrees centigrade 4-at 30 degrees centigrade 5-at 40 degrees centigrade 6-at 50 degrees centigrade 3-16 degrees centigrade 1-at 12 degrees centigrade Measurements of leaf size and number were taken every two weeks. Describe what is wrong with this approach