Animal cells do not directly contact pure water. Which type of solution are
our cells bathed in?
A. hypertonic
B. hypotonic
C. isosmotic
D. isotonic

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

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

What is the role of dna ligase in the elongation of the lagging strand during dna replication?