Choose the best answer

1			The epidermis fights microbial infections by Need a Hint?
			A)	making the surface of the skin acidic.
			B)	excreting lysozyme to attack bacteria.
			C)	producing mucus to trap microorganisms.
			D)	all of these.
2			Cells that target and kill body cells infected by viruses is are Need a Hint?
			A)	macrophages.
			B)	natural killer cells.
			C)	monocytes.
			D)	neutrophils.
3			A molecule present on the plasma membrane that induces an immune response is called Need a Hint?
			A)	an antigen.
			B)	an interleukin.
			C)	an antibody.
			D)	a lymphocyte.
4			Which one of the following acts as the "alarm signal" to activate the body's immune system by stimulating helper T cells? Need a Hint?
			A)	B cells
			B)	interleukin-1
			C)	interleukin-2
			D)	histamines
5			Cytotoxic T cells are called into action by the Need a Hint?
			A)	presence of histamine.
			B)	presence of interleukin-1.
			C)	presence of interleukin-2.
			D)	B cell stimulating factor.
6			The immunoglobin ________ is involved in the primary response to an invading microorganism, and ________ is involved in the secondary response. Need a Hint?
			A)	IgG / IgM
			B)	IgM / IgE
			C)	IgE / histamines
			D)	IgM / IgG
7			How does your body detect millions of different antigens? Need a Hint?
			A)	The few hundred immunoglobulin genes can be rearranged or can undergo mutations to form millions of antibody molecules.
			B)	There are millions of different antibody genes.
			C)	The few hundred immunoglobulin genes undergo antigen shifting.
			D)	Each B cell has a different set of immunoglobulin genes, and so the activation of different B cells produces different antibodies.
8			The blood from a person with an AB blood type Need a Hint?
			A)	would agglutinate with anti-A antibodies only.
			B)	would agglutinate with anti-B antibodies only.
			C)	would agglutinate with both anti-A and anti-B antibodies.
			D)	would not agglutinate with either anti-A or anti-B antibodies.
9			The HIV virus is particularly dangerous because it attacks Need a Hint?
			A)	cells with the CD4+ coreceptor.
			B)	helper T cells.
			C)	60 to 80% of circulating T cells in the body.
			D)	all of these.
10			Diseases in which the person's immune system no longer recognizes its own MHC proteins are called Need a Hint?
			A)	allergies.
			B)	autoimmune diseases.
			C)	immediate hypersensitivity.
			D)	delayed hypersensitivity.