he molecules that for " The rungs of the ladder" in a DNA molecule are called ...
Purines and PyrimadinesPhosphoric acid and ribose
Phosphoric acid and ribose
Acids and Bases
Uracil and Asparagine
Purines and Pyrimadines.
The rungs of the ladder are pairs of four types of nitrogen bases from two groups of organic molecules - purines and pyrimidine s.