What are leukocytes primarily responsible for?

Leukocytes, also known as white blood cells, play a crucial role in the immune system, which is primarily responsible for defending the body against infections and diseases. Their main function is to identify and eliminate pathogens, such as bacteria, viruses, and parasites, that invade the body. They are equipped with various mechanisms to recognize foreign substances and neutralize them, thereby maintaining the overall health and integrity of the organism.

Leukocytes can be further classified into different types, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specific roles in the immune response. For example, neutrophils are often the first responders to infection, while lymphocytes are crucial for adaptive immunity, recognizing specific antigens and creating a targeted response.

The other options relate to functions not associated with leukocytes. Specifically, storing nutrients is primarily a function of cells like adipocytes and hepatocytes, transporting oxygen is the role of red blood cells, and producing hormones is typically associated with endocrine cells and glands. These distinctions highlight the specialized functions of different cell types in the body.