How old is a sample of Carbon-14 that is 25% C14 and 75% Nitrogen 14?

What is the next step in the process after a substrate enters the active site of an enzyme

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

What does spontaneous generation mean?