Nitrogenous base that occurs in rna but not in dna
(a) deoxyribose
(b) ribose
(c) uracil
(d) cytosine
(e) thymine

Which of the following statements best distinguishes a hypothesis from a theory? a. theories are hypotheses that have been proved. b. hypotheses are guesses; theories are correct answers c. hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. theories are proved to be true; hypotheses are often contradicted by experimental results.