Question

Which of the following acts as a control for bowl 7 and 4?

• A. $1$ and $3$
• B. $1$ and $6$
• C. $1$ and $10$
• D. $2$ and $5$
• E. $2$ and $8$

Answer 1

The correct option is C $1$ and $10$

In order to determine the amount of carbon dioxide content in the water, the bowls with the same content are exposed to different conditions. If one needs to determine the difference in carbon content when placed in dark and exposed to light, control for bowl 7 will be bowl 1 as the content in the bowl is same but they are exposed to different conditions. Control for bowl 4 will be bowl 10 as the content in the bowl is same but they are exposed to different conditions.

Thus, the correct answer is option C.