Question

The human immune response:

	a.	has evolved to recognize microbes but not human tissue.
	b.	has evolved so that it does not interact with the bacteria that live in our gut.
	c.	has evolved to distinguish self from non-self.
	d.	has evolved so that all humans have the same antigenic specificity.
	e.	I don’t know the answer to this question.
	f.	all of the above are equally correct.

Please provide support/justification for your answer to the human immune response question.

The initial response (first day) of the immune system to Streptococcus pneumoniae is the same as the initial response of the immune system to Escherichia coli because

	a.	the immune response to all bacteria is essentially the same.
	b.	both bacteria share one identical antigenic epitope.
	c.	I don't know the answer to this question.
	d.	both secrete the same toxin.
	e.	both cause diarrhea.
	f.	both are rod-shaped.

Please provide support/justification for your answer to the similar initial response of the immune system to Streptococcus and Escherichia question.

Selection for antibiotic resistance (always) relies on distinguishing between differences in:

	a.	I do not know the answer to this question.
	b.	genotype
	c.	phenotype
	d.	physiology
	e.	morphology.

Please provide support/justification for your answer to the antibiotic resistance relies on ..., question.