Aperson with blood type o would
a. lack both antigens a and b on their erythrocytes.
b. are universal recipients.
c. possess neither anti-a nor anti-b antibodies circulating in their blood plasma.
d. possess both a and b on their erythrocytes.

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.