G locate and identify the functional groups in (a) propylene glycol, one of the major ingredients used in electronic cigarettes; (b) glutaric acid, produced in the body during the metabolism of lysine and tryptophan; (c) lactic acid, from sour milk; and (d) phenylalanine, an amino acid found in proteins.

Which statement best explains why cells were observed in more detail using a compound microscope than a simple microscope? a compound microscope has greater magnification ability than a simple microscope. the compound microscope was invented before the simple microscope. a compound microscope is much easier to manufacture than a simple microscope. compound microscopes were more common than simple microscopes.