Which is not true about secondary immunoglobulin response is: March 2011
Ans. B: Takes 5 days to appear The secondary response is prompt, powerful and prolonged, with a shoer or negligible lag phase and much higher level of antibodies that lasts for long period (Antibody is predominantly IgG) Immune response The first time a harmful antigen is encountered in the body it triggers the primary immune response. Antibody formed in primary immune response is predominantly IgM For many days after an antigen has entered the body there are no antibodies produced in the bloodstream to fight the antigen. This lag period can last for as little as 10 days or as long as 4 weeks. During the lag phase, B-lymphocytes are preparing to become active so they can sta to divide and begin to produce antibodies. Soon antibodies specific for the harmful antigen begin to appear in the bloodstream and increase until they level off and then slowly decrease until the antibodies are barley detectable. Slowly as the primary immune response progresses, the quality of antibodies improves. The antibodies that are more effective in killing the invading antigens become predominant. The secondary immune response occurs after an antigen that has already been encountered reappears. For example, if someone had recovered from the flu and later encounters the same strain of that virus antibodies that were made specifically for that antigen will rise dramatically with almost no lag period. Also after the antigen has been killed the antibodies fall even slower than they did in the primary immune response. The most dominant antibodies are what signals the other immune cells to attack, thus the immune system is said to memory response.
Predominance of IgG
Takes 5 days to appear
Depends on immunologic memory
May be repeated in physiological limits