Immune System

Which of the following best describes an example of a nonspecific external response to infectious agents?

• Phagocytes consume infectious agents through the process of endocytosis.

• The presence of infectious agents causes inflammation and swelling in localized areas.

• Sweat creates an acidic environment, which inhibits growth of infectious agents.

• Memory B cells recognize infectious agents and destroy them before they can enter the body.

Which of the following best describes an example of a specific internal response to harmful bacteria?

• Skin serves as a physical barrier that prevents bacteria from entering the body.

• Saliva contains enzymes that destroy bacteria and prevent infection.

• Bacterial infection causes the release of histamine, which leads to inflammation and swelling.

• Antigens trigger the production of antibodies, which mark bacteria for destruction.

Which of the following best describes an example of a specific immune response to pathogens?

• Cytotoxic T cells are activated and destroy cells that pathogens have invaded.

• Fever increases body temperature and speeds up the body’s reaction to pathogens.

• Phagocytes identify cells invaded by pathogens and mark them for destruction.

• Mucus traps pathogens and destroys them before they can enter the body.

Which of the following best describes steps that take place during a humoral immune response?

• T cells divide into helper T cells and cytotoxic T cells to fight infectious agents.

• Cytotoxic T cells destroy pathogens that are detected by memory T cells.

• Memory B cells divide and produce plasma cells that engulf and destroy pathogens.

• B cells bind to an antigen and produce plasma cells and memory B cells.

Which of the following happens when infected body cells are detected during a cell-mediated immune response?

• Helper T cells divide and activate cytotoxic T cells, which destroy the infected cells.

• Memory T cells divide and form helper T cells, which destroy the infected cells.

• B lymphocytes divide and activate memory B cells, which destroy the infected cells.

• Memory B cells divide and form plasma cells, which destroy the infected cells.

Which of the following best describes what causes plasma cells to form during a humoral immune response?

• Memory B cells signal phagocytes to attack infected cells and divide, producing plasma cells.

• The antibodies on the surface of B cells bind to antigens, and the B cells grow and divide, producing plasma cells.

• The antigens on the surface of a pathogen attack healthy cells, and the resulting inflammation signals helper T cells to divide, producing plasma cells.

• Memory T cells recognize antigens and signal T lymphocytes to divide, producing plasma cells.

The children in a middle school classroom are all exposed to chicken pox one week. Among these students are John, who had chicken pox when he was much younger, and Sara, who has never had chicken pox. Which student do you expect would be less likely to become ill with chicken pox following this exposure and why?

• John: he has naturally acquired active immunity to chicken pox from his previous exposure.

• Sara: she has naturally acquired passive immunity to chicken pox from exposure to other students.

• John: the pathogens that cause chicken pox will no longer be able to enter his body.

• Sara: since she has not suffered from chicken pox, her immune system is probably stronger than John’s.

Which of the following types of immunity do you expect would be the most effective in preventing a particular illness for a long period of time and why?

• Active immunity: it allows the body to gain antibodies from several other outside sources.

• Active immunity: it allows development of memory cells that can later help fight infection.

• Passive immunity: it requires less energy to be expended by the individual overall.

• Passive immunity: it does not require the body to be subjected to repeated vaccine injections.

Which of the following best explains a long-term disadvantage of antibiotic use in patient care?

• Antibiotics are more expensive to manufacture and distribute than vaccines.

• Vaccines are covered by most health care plans, while many antibiotics are not.

• Most vaccines are harmless, while some antibiotics have dangerous side effects.

• Misuse of antibiotics can lead to an increase in antibiotic-resistant strains of bacteria.

Antibiotics are used to treat what type of pathogen?

• Bacteria

• viruses

• Fungi

• parasites