Which of the following would you need in order to compare the effect of two different fertilizers on plant growth? a. a way to measure plant growth b. a cardboard box to cover one plant c. a variety of plant species d. a selection of soil types

Why do some dna fragments move farther than others during gel electrophoresis? a. because their shapes are different b. because they are different types of molecules c. because the samples are different colors d. because their masses are different