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Module 27 Lesson 2 Progress Check

Prompt

Read module 27 lesson 2 and complete "Check Your Progress" questions #1, 2, 3, 6, 7 on p.733.

Response

  1. Compare specific and nonspecific immune responses.

    The specific immune response is adaptive, targeting specific pathogens with memory cells for faster response upon reexposure. It involves lymphocytes like T and B cells which recognize specific antigens. In contrast, the nonspecific immune response (or innate immunity) acts as the first line of defense, responding to pathogens in a generic way without antigen specificity, involving barriers, phagocytic cells, and inflammatory responses.

  2. Describe the steps involved in activating an antibody response to an antigen.

    The antibody response begins when an antigen is recognized and ingested by an antigen-presenting cell (APC), such as a dendritic cell. The APC then presents antigen fragments on its surface in complex with MHC II molecules, interacting with CD4+ T cells. This interaction, along with costimulatory signals, activates the T cells, which in turn help activate B cells. B cells then differentiate into plasma cells that produce and secrete antibodies specific to the antigen.

  3. Identify ways passive and active immunity can be acquired.

    Passive immunity is acquired by the transfer of antibodies from another source, such as maternal antibodies transferred to a fetus through the placenta or to an infant via breast milk, or through antibody-containing blood products. Active immunity is acquired through exposure to an antigen, either by infection or vaccination, leading to the body producing its own antibodies and memory cells which confer long-term protection.

  4. Hypothesize what happens when an HIV strain mutates such that viral-replication drugs are no longer effective.

    When an HIV strain mutates such that viral-replication drugs are no longer effective, the virus can resume its replication unimpeded, potentially leading to an increase in viral load and a deterioration in the patient's immune function. These mutations may confer resistance to specific antiretroviral drugs, making them ineffective and necessitating a change in the medication regimen to control the infection.

  5. Evaluate the effects of severe combined immune deficiency on a child born without T cell immunity.

    A child born with severe combined immune deficiency (SCID) without T cell immunity is highly susceptible to infections, including opportunistic infections that are typically harmless to individuals with normal immune systems. Without functional T cells, the child cannot mount effective cellular immune responses, leading to severe, recurrent, and potentially life-threatening infections. Treatment often involves isolation to protect from pathogens and may require bone marrow transplantation to restore immune function.