You were introduced to the concept of a standard curve. When creating a standard curve, the independent variable (the variable that is changed or manipulated) is plotted on the x-axis and the dependent variable (what we measure when the independent variable is changed) is plotted on the y-axis

Question

a. In part 4, you will create standard curves to help you determine the size of the insect and Wolbachia DNA fragments that you amplified using PCR. The standards in this case are the DNA fragments of known sizes in you DNA ladder. In this scenario, what is the independent variable?

b. What is the dependent variable?

c. If you know the distance that a fragment of DNA migrated through a gel, which variable could you use this information to solve for, the independent or the dependent variable?

Answer 1

a. In this scenario, the independent variable is the size of the DNA fragments in the DNA ladder. This is what you are changing or manipulating when creating the standard curve.

b. The dependent variable is the distance that the DNA fragment migrated through the gel. This is what you are measuring in response to the sizes of the DNA fragments.

c. If you know the distance that a fragment of DNA migrated through a gel, you could use this information to solve for the dependent variable. You would use the distance migrated to determine the size of the unknown DNA fragment based on the standard curve created from the known sizes of the DNA ladder.