The umbilical cord connects the embryo to the
a. uterus.
b. fetus.
c. placenta.
d. vagina.

How water is moving through the ecosystem ?

What are the three groups of atoms that make up amino acids called

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.