7) Which of the following statements is true about the IgM
of humans?
(a) IgM can cross the placenta (b) IgM can protect the
mucosal surface
(c) IgM is produced by high-affinity plasma cells (d) IgM
is primarily restricted in the circulation
Answers
Answer:
The answer is (c)
Explanation:
The earliest antibody isotype to appear during evolution, ontogeny, and immunological responses is immunoglobulin (Ig) M.
There are a few characteristics of IgM:
1. It is the first antibody produced during an initial antigen challenge by plasma cells.
2. The first immunoglobulin, IgM, is discovered around 20 weeks of human embryonic development.
3. IgM antibody, unlike IgG antibody, which gives passive immunity to the foetus, is unable to pass the placenta due to its size.
4. It's also the first antibody to react during infection.
5. Because of its higher complement activation, the IgM class of antibodies identifies a wide range of pathogenic antigens and is extremely active in cytotoxic and cytolytic reactions.