Which of the following statements best justify the inclusion of group 2 as one of the controls in the experiment? a) i will show whether the changes observed in group 1 depend on the metabolic activity of boll bacteria b) will show whether the changes observed in group 1 depend on the type of plants used in the experiment. c) it will show the average growth rate of seedings that are maintained in a nonsterile environment d) i will show the changes that occur in the roots of seedlings following an infection by soll bacteria.

(A) It will show whether the changes observed in group 1 depend on the metabolic activity of soil bacteria.

Explanation:

A control in an experiment is used to show the effects of one or more variables or chemicals on the experimental constraints such as the metabolic activity. Experimental results in the presence and absence of a given variable or chemical are recorded and compared to determine the effects of the chemical on the experimental results.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.