Final answer:
Pattern recognition receptors (PRRs) are found on the surface of both macrophages and neutrophils, and these receptors play a key role in the innate immune system by recognizing and leading to the destruction of pathogens. he correct answer to the question is 'B.
Step-by-step explanation:
Pattern recognition receptors (PRRs) are crucial components of the innate immune system. They are expressed on the surface of macrophages and dendritic cells, as well as other immune cells like neutrophils. PRRs are responsible for recognizing pathogen-associated molecular patterns (PAMPs) which are molecular signatures found on pathogens such as viruses, bacteria, and parasites. This recognition leads to the activation of the immune response, including the engulfment and destruction of the pathogens. Macrophages and neutrophils, being phagocytic cells, play a significant role in this process by directly consuming and deactivating the recognized pathogens.
Toll-like receptors (TLRs) are a well-known type of PRR found on these phagocytes. These receptors are capable of identifying molecules that are common to groups of pathogens, but not present in host cells, allowing the immune system to detect foreign invaders. Therefore, when asked which cells have PRRs, options macrophages and neutrophils are both correct, but combining them provides the most complete answer. Hence, the correct answer to the question is 'B. macrophages and neutrophils'.