Each rung of the DNA ladder is made up of a A( single nitrogen base
B( pair of nitrogen bases
C( pair of carbon bases
D( single carbon base

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass