Question 40

White blood cells are responsible for fighting infection.

White blood cells play a crucial role in the immune system by identifying and combating pathogens such as bacteria and viruses, thereby protecting the body from infections.

A) delivering oxygen

This option is incorrect because delivering oxygen is the primary function of red blood cells, not white blood cells. Red blood cells contain hemoglobin, which binds to oxygen and transports it throughout the body.

B) blood clotting

This option is also incorrect as blood clotting is primarily facilitated by platelets, along with certain plasma proteins. White blood cells do not play a significant role in the coagulation process.

C) fighting infection

This option is correct as white blood cells, or leukocytes, are essential components of the immune system. They actively seek out and destroy pathogens, making them vital for fighting infections.

D) making synovial fluid

This option is incorrect because synovial fluid is produced by synovial cells found in the joints, not by white blood cells. White blood cells do not have a role in the synthesis of synovial fluid.

Conclusion

The correct answer, option C, highlights the primary function of white blood cells in the immune response against infections. The other options fail to recognize the specific roles of various blood components, such as red blood cells and platelets, illustrating a fundamental understanding of the distinct functions within the circulatory and immune systems.