Question

A researcher wants to study how exposing corn to a genetically modified strain of E.coli would affect the growth of the com. The E. coli is genetically modified to produce a natural pesticide. He hopes to be able to provide farmers with an alternate source of pesticides that doesn't involve using harmful chemicals. Match the following parameters with the proper experimental design element. Question Corn exposed to E. coli that is not genetically modified Amount of E. coli the corn is exposed to All Answer Choices Whether the E. coli has been genetically modified control The biomass of the corn constant The length of a corn stalk independent variable Time allowed to grow dependent variable

Answer 1

Control is same set of experiment with one parameter or aspect different from the actual experiment (test) , so that the results of actual experiment can be compared with that of the control experiment - corn exposed to E coli that is not genetically modified.

Constant - parameters which are same for the actual (test) and the control experiment groups so that the results (dependent variable) from both set of experiments can be compared- Amount of E coli corn is exposed to, time allowed to grow.

Independent variables are the variables decided by the researcher- whether E coli is genetically modified

Dependent variables are those which are measured as a response to the independent variable. The biomass of the corn, the length of the corn stalk.