Florida Basic Recruit Training Program High Liability (First Aid) Practice Exam

Which type of blood cells destroy bacteria and other disease organisms?

1. Platelets

2. Red blood cells

3. White blood cells

4. Plasma

The correct answer is: White blood cells

White blood cells, also known as leukocytes, play a crucial role in the immune system by identifying and eliminating bacteria, viruses, and other pathogens that can cause disease. They are essential for the body's defense against infections. There are several types of white blood cells, each with specific functions; for example, neutrophils are particularly effective at engulfing and destroying bacteria, while lymphocytes are involved in recognizing foreign invaders and mounting appropriate immune responses. In contrast, red blood cells primarily function to transport oxygen from the lungs to the body's tissues and return carbon dioxide from the tissues back to the lungs for exhalation. Platelets are cell fragments that play a key role in blood clotting, helping to stop bleeding when injuries occur. Plasma is the liquid component of blood that carries cells, nutrients, hormones, and waste products but does not have a direct role in fighting disease. Thus, the specific responsibility of white blood cells in combating infections makes them the correct answer in this context.