Question

Carlo is wondering what causes plants to grow at different rates. Carlo’s hypothesis is “Plants will grow more when the day is longer.” What would be the difference between the test group and the control group in this experiment?

type of soil
type of plants
exposure to sunlight
method for measuring the growth

Answer 1

Exposure to sunlight is the answer

Answer 2

Exposure to sunlight

Step-by-step explanation:

Carlo's hypothesis is "Plants will grow more when the day is longer." We can then assume that the exposure to sunlight is what Carlo hypothesizes as a factor to plant growth because he is talking about the length of daytime.

In order to eliminate other factors, the type of soil, plant and method of measure must remain the same.

So again, the answer is exposure to sunlight.