Final answer:
PAMPs are recognized by pattern recognition receptors (PRRs), such as Toll-like receptors, which are present on the innate immune system's cells like macrophages and dendritic cells.
Step-by-step explanation:
PAMPs (pathogen-associated molecular patterns) are molecular structures found on various pathogens and are recognized by the innate immune system. Specifically, PAMPs are identified by pattern recognition receptors (PRRs), which are present on cells such as macrophages and dendritic cells. These receptors are critical for the initial response to infection, as they promote pathogen engulfment and destruction. One type of PRR is the Toll-like receptor (TLR), which is capable of recognizing molecules shared by pathogens that are distinct from host molecules, thereby enabling the immune system to detect the presence of an invading pathogen.
Therefore, the correct answer to the student's question about what recognizes PAMPs is c) Pattern recognition receptors (PRRs).