In his transformation experiments, what did Griffith observe?
A) Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.
B) Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic.
C) Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains.
D) Mice infected with a pathogenic strain of bacteria can spread the infection to other mice.
A
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Acetylcholine receptors can be differentiated by their ability to be activated by substances such as ________ and ________.
Fill in the blank(s) with the appropriate word(s).
Protons and neutrons are located in the ________ of an atom
Fill in the blank(s) with correct word
Pepsinogen is made by ______ cells of the ________.
A. langerhans; pancreas B. bile; liver C. parietal; stomach D. cheif; stomach E. mucus; large intestine
First line of defense may be described as
A) the release of prostaglandins and leukotrienes in response to microbes. B) intact skin, mucous membranes, sebum, tears, and so forth. C) damage resulting in cell lysis. D) the coating of a pathogen by complement. E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.