#Question id: 1985
#Unit 4. Cell Communication and Cell Signaling
Which of the following is the last line of defense against an extracellular pathogen?
#Question id: 1986
#Unit 4. Cell Communication and Cell Signaling
The following events occur when a mammalian immune system first encounters a pathogen. Which shows the correct sequence in which they occur?
I. Pathogen is destroyed.
II. Lymphocytes secrete antibodies.
III. Antigenic determinants from pathogen bind to antigen receptors on lymphocytes.
IV. Lymphocytes specific to antigenic determinants from pathogen become numerous.
V. Only memory cells remain.
#Question id: 1987
#Unit 4. Cell Communication and Cell Signaling
A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to
#Question id: 1988
#Unit 4. Cell Communication and Cell Signaling
What are CD4 and CD8?
#Question id: 1989
#Unit 4. Cell Communication and Cell Signaling
Which of the following are T cells of the immune system?
#Question id: 1990
#Unit 4. Cell Communication and Cell Signaling
B cells interacting with helper T cells are stimulated to differentiate when