Which of the following is NOT a function of the complement system of the blood?
A) Aiding the immune response by selectively binding to specific foreign antigens.
B) Increasing opsonization by enhancing the phagocytosis of foreign antigens.
C) Using a chemotaxis effect to attract greater numbers of macrophages and neutrophils to an infection site.
D) Directly lysing cells by rupturing the cell membranes of foreign cells.
Explanation
The complement system is a group of proteins found in the blood and is a part of the innate immune system, which does not change over a person’s lifetime and does not react to specific antigens, but rather provides broad defenses against many types of foreign cells or substances. As such, it does not selectively bind to specific antigens as (A) says – this is the function of antibodies produced by B cells. Thus (A) is the correct answer.
The remaining choices are all functions of the complement system.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT Advisor using the form below. No obligation, just expert advice.