Question

A scientist is testing the effectiveness of Drug X on cancer. She gives a small amount of the drug to mice that have cancer. She gives each mouse a different amount from 1 to 10 grams, and then measures the size of the tumor in each mouse before the drugs and two weeks after the drugs. She gives one of the mice sugar instead of Drug X. What is her independent variable in this experiment?
A. The amount of Drug X given to the mice.
B. The mouse that received sugar instead of Drug X.
C. The size of the tumor before Drug X
D. The size of the tumor after Drug X

Answer 1

Answer:

Option A, The amount of Drug X given to the mice.

Explanation:

In an experiment, an independent variable is not the subject of the experiment and hence the impact of independent variable is studied on the depended variable.   An independent variable does not change or remains constant throughout the experiment.  

Here in this case-

a) Independent variable - is the amount of drug (X) given to the mice having cancer.  

b) Dependent variable - is the mice having cancer on which the effect of drug will be studied .  

Therefore, option A is correct

Answer 2

C. The size of the tumor before because it doesn't depend on Drug X's effects or the effects/changes from the scientist.