Which of the following blood cells is responsible for fighting infections?

White blood cells, also known as leukocytes, play a crucial role in the immune system by defending the body against infections. They are specifically designed to identify and eliminate pathogens, such as bacteria, viruses, and other foreign invaders. There are several types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specialized functions in immune response.

These cells can move freely through the bloodstream and can also migrate into tissues where infections are taking place. Upon encountering pathogens, white blood cells can either engulf and digest them or produce specific antibodies that target these invaders for destruction.

In contrast, red blood cells are primarily responsible for transporting oxygen from the lungs to the tissues and returning carbon dioxide from the tissues to the lungs. Platelets are involved in blood clotting and are crucial for preventing excessive bleeding but do not play a direct role in immune responses. Plasma cells, a type of differentiated B cell, are specifically involved in producing antibodies but are a subset of white blood cells rather than a separate category. This highlights the importance of white blood cells as the primary defenders against infections in the body.