1. Which of the following is/are true about commensal organisms? a. about 500,00

Question

1. Which of the following is/are true about commensal organisms? a. about 500,000 in/on human body b. protect against disease by preventing colonization by pathogens c can become opportunistic d. all of the above e. b and c 2. Match each phrase with innate (I), adaptive (A) or neither (N). -neutrophil is effector cell has "memory" mechanisms are constant during response -response takes years to develop _ mechanisms improve during response 3. Which is not a pathogen? a. Ebola virus c. Methicillin resistant Staph aures d. Candida bCytotoxic T-cell The primary lymphoid tissues are thymus and spleen 4. thymus and lymph nodes b. c. thymus and bone marrow d. thymus and tonsils a. 5. True statements about the first barrier against pathogens include all of the following except a. b. c. d. mucosal surfaces are protected by mucus produced by goblet cells the basic (high pH) environment of the GI tract is a defense it is composed of epithelial cells mucosal surfaces can secrete antimicrobial substance such as sebum and defensins 6. Which are true about dendrite cells? a. initiate adaptive response b. carry pathogen proteins to lymphoid tissue c. release cytokines d. a and b e. a and c 7. Which is true about the adaptive immune response? a. macrophages and natural killer cells are used b. starts within hours of pathogen invading barrier c. antibodies produced to pathogen or its proteins d. complement system very important 8. TorF Innate immune mechanisms eliminate pathogens before symptoms can begin. 9. Pathogens can cause damage by a. exotoxins b. endotoxins c. direct cytopathic effects d. all of the above

Explanation / Answer

Ans 1: Commensal microorganisms live with us without causing disease. Commensal microorganisms benefits includes that they help process digested food and make vitamins. Protect against disease by preventing colonization of pathogenic microorganisms, some commensals produce antibacterial proteins to kill off other bacteria.

Ans 2: Innate: neutrophil is effector cell

has memory: Adaptive: Memory, enhanced responses to repeated exposures to same antigen

responce mechanism are constant during responce: recognition mechanisms of innate immunity is a rapid response (hours), fixed, limited number of specificities and constant during response

responce takes years to develop: adaptive

mechanism improves during responce: Adaptive Immunity has a slow response, is variable, has numerous highly selective specificities, and improves during the response.

Ans 3: Activated cytotoxic T cells circulate in blood and lymph. Cytotoxic T cells bind to the self-nonself complex. They directly attack and kill cells, destroy all infected or abnormal cells.

Ans 4: Main function of primary lymphoid tissues is the generation of mature, but antigen naive T and B cells. Development of antigen recognition. Rearrangement of antigen receptor genes. Primary lymphoid tissues are thymus and bone marrow.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.