It is difficult to obtain a toxic dose of a vitamin from a food source alone

The germ theory states that: a. infectious diseases can be cured with antibiotic therapy. b. most microorganisms are harmful to humans

c. health care workers should wash their hands frequently. d. bacteria cause many specific diseases.

The ________ cells are cells that do not transmit impulses, but function as support cells for neurons and never lose their ability to divide. 

Fill in the blank(s) with the appropriate word(s).