What distinguishes a hypothesis from a theory? a. a theory is a scientific explanation. b. a theory is testable. c. a theory explains a natural phenomenon. d. a theory is backed up by repeated observations and tests.

Which direction does the energy flow in this energy pyramid ?

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

Which of the following does not make up ground substance of connective tissue? hyaluronic acid elastic fibers glycosaminoglycan proteoglycan