Which best describes how dna is used as a molecular clock?
the number of mutations in dna is compared between two species.
the total amount of dna is compared between two species.
the percent of carbon in dna is compared between parent and offspring.< the total mass of dna is compared between parent and offspring.

Greg drew a diagram to compare two of the fundamental forces. which labels belong in the areas marked x, y and z? gravitational force electromagnetic force x. attractive y repulsive z: infinite range x: infinite range y attractive z. repulsive x. always attractive y: infinite range z: attractive or repulsive x. attractive or repulsive y infinite range z: always attractive