Question

mario performed an experiment to determine if photosynthesis was affected by the amount of light that a plant received. the data from his experiment are shown in the table below.

amount of light (hours)	number of plants	average volume of oxygen produced (ml)
6	4	2.0
10	4	5.0

what could he have done to increase the validity of his data?
reduce the number of plants.
remove the 1 - hour group.
add a 0 hours control.
measure the oxygen in liters.

Explanation:

To increase data validity in an experiment, a control group is important. Adding a 0 - hours control group would provide a baseline to compare the effects of different light - exposure times on photosynthesis (measured by oxygen production). This helps to isolate the variable of light exposure and rule out other factors.

Answer:

Add a 0 hours control.