11. Cytotoxic T-cells can be recognized by which of the following cell surface marker?

A. CD4
B. CD7
C. CD8
D. CD9

12. Which is not an antigen-presenting cell (or APC)?

A. B cell
B. Polymorphonuclear leukocyte (or PMN)
C. Dendritic cell
D. All of the above

13. Chemically an antigen maybe

A. lipid
B. protein
C. polysaccharide
D. any of these

14. T cell receptors (or TCR) on CD4+ T cells

A. recognize peptides not associated with MHC molecules
B. recognize peptides associated with MHC class I molecules
C. recognize peptides associated with MHC class II molecules
D. are secreted out into the environment to bind antigens

15. Which of the following proteins would not need a localization signal?

A. A nuclear protein
B. A cytosolic protein
C. A protein bound to the endoplasmic reticulum (ER) membrane
D. A cell surface protein