One-year-old Matthew always seems to be sick. When his blood is tested, there are no antibodies. The physician concludes that the child is lacking a. the ability to develop an inflammatory response. b. helper T-lymphocytes. c. cytotoxic T-lymphocytes. d. B-lymphocytes.

Explain why each choice (a-d) is correct or incorrect.  Which statement is true about T cells? a. They usually directly recognize antigens, which then activates a subpopulation of killer cells b. Their proliferation is enhanced by interleukins 1 and 2. c. Once activated, they cannot secrete cytokines. d. They will develop into cytotoxic T cells if antigen is complexed with class II MHC proteins.

Which of the following pairs is mismatched? a. plasma cell: mediation of phagocytosis and killing of microorganisms in the plasma b. megakaryocyte: formation of platelets c. dendritic cell: activation of adaptive immune responses d. natural killer cell: develops from a common lymphoid progenitor e. neutrophil: formation of pus f. regulatory T cell: inhibition of T-cell activity.

Why are most unimmunized children protected against diseases such as measles?Choose one: A.  They lack the host cells for viral replication. B.  They are protected by herd immunity. C.  They have developed immunity toward the measles virus. D.  They still have circulating maternal antibodies.

The followings are functions of antibody eliminating unknown particles or cells which enter into the body, except... A. Attach to the active side of particle or cell that enters into the body B. Make easier of macrophage to phagositosize unknown particle or cell that enters the body C. Precipitate the unknown particle that dissolves in body fluid  D. Initiate the working system of complement E. Eliminate bacteria that grows on endosome of macropahge

The lymphatic tissues/organs illustrated below contain which of the following types of cells? 1.  reticular cells 2.  macrophages 3.  B lymphocytes 4.  T lymphocytes Choose from the following: (A) 1, 2 and 3 (B) 1, 2, and 4 (C) 2, 3, and 4 (D) 1, 3, and 4 (E) 1, 2, 3, and 4