Question

What is the difference between natural killer cells and macrophages?

a) Natural killer cells are phagocytic, while macrophages release cytotoxic substances.
b) Natural killer cells recognize infected cells and release toxic granules, while macrophages engulf pathogens.
c) Natural killer cells are part of the adaptive immune system, while macrophages are part of the innate immune system.
d) Natural killer cells produce antibodies, while macrophages directly attack viruses.

Answer 1

Natural killer cells recognize and kill infected cells, while macrophages engulf and digest pathogens.

Step-by-step explanation:

Natural killer (NK) cells and macrophages are both types of immune cells that play important roles in the body's defense against infection. However, there are some key differences between the two:

1. Natural killer cells: These cells are part of the innate immune system and are able to directly recognize and kill infected or abnormal cells. They release toxic granules that trigger apoptosis, or programmed cell death, in the target cells.
2. Macrophages: Macrophages are also phagocytic cells, but their main function is to engulf and digest pathogens or other foreign particles. They can also produce a wide range of chemicals and proteins that help regulate the immune response.

In summary, natural killer cells primarily kill infected cells through the release of toxic granules, while macrophages mainly engulf and digest pathogens. Natural killer cells are part of the innate immune system, while macrophages are versatile cells that can act as scavengers and antigen-presenting cells.