How does the immune system recognize a foreign cell?
A)The presence of toll-like receptors.
B)The presence of organ-specific phagocytes.
C)The presence of pathogen-associated molecular patterns.
D)The presence of complement.

Question

Quizplus · Accepted Answer

The immune system recognizes a foreign cell by the presence of pathogen-associated molecular patterns (PAMPs). PAMPs are molecules that are unique to microorganisms and are recognized by pattern recognition receptors (PRRs) on immune cells.

Answer: A
 Toll-like receptors (TLRs) are a type of PRR and are involved in the recognition of PAMPs. They are expressed on various immune cells and respond to different types of PAMPs, such as bacterial cell wall components, viral RNA, and flagellin.

Answer: D
 Complement is a system of proteins in the blood that can be activated by the presence of foreign cells or molecules. It can lead to the destruction of the foreign cell through a process known as lysis. However, complement alone is not sufficient for the recognition of foreign cells.

How Does the Immune System Recognize a Foreign Cell