How does water on a road surface affect tire friction
a: adds to normal dry friction
b: increases or decreases friction depending on tire tread
c: decreases friction
d: eliminates all friction

Immature bone cells, or osteoblasts, manufacture a protein called osteoid as well as several hormones. because of this, we would expect osteoblasts to contain numerous a) nuclei. b) ribosomes. c) lysosomes. d) golgi bodies.

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

How are fossils used to date organisms?