Immune System
Which of the following statements is false regarding B cells?

B cells that recognize high concentrations of antigens (self) in the absence of other signals undergo apoptosis in the bone marrow
B one marrow stem cells migrate to the thymus and develop into B cells
B cells can undergo class switching and produce a different antibody type
B cells synthesize antibodies and put them on their cell surface

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Immune System
Polymorphonuclear leukocytes (or PMNs)

are derived from bone marrow stem cells
are a type of phagocyte that can engulf and kill bacteria
can be attracted to the site of an infection following activation of complement
All of these

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Immune System
The role of the M cell is to

induce apoptosis in virus-infected small intestinal epithelia cells
they use their cilia to propel mucus out of the small intestine
trap virus in mucus and prevent entry
pass bacteria or virus to underlying macrophages for processing and presentation of antigen

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Immune System
Which of the following is correct for isoantigens?

They are antigens found in some members of different species
They are antigens found in all members of a species
They are antigens found in some members of a species
They are antigens found in all members of different species

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