Question

An experiment was performed where 20 radish seedlings were grown in red, blue, green, and white light. The height of plants was measured once per week for 8 weeks. Name TWO things that should be kept constant.

Answer 1

Two things that should be kept constant in the experiment are the number of seedlings and the amount of water provided to each seedling.

Step-by-step explanation:

In the experiment, two things that should be kept constant are the number of seedlings and the amount of water provided to each seedling.

Keeping the number of seedlings constant, ensures that there is an equal representation of each condition (red, blue, green, and white light) and reduces any potential bias.

Keeping the amount of water constant helps to ensure that the only variable being tested is the effect of different light colors on plant growth and not the effect of varying water levels on plant height.