Question

White blood cells travel through the blood and are a part of the cardiovascular system. Which other system also contains white blood cells?

A. the integumentary system
B. the respiratory system
C. the immune system
D. the endocrine system

Answer 1

C the immune system. The white blood cells are phagocytes. This means the kill harmful cells such as bacteria or viruses.

Answer 2

White blood cells fight illness and heal, making the answer C. The immune system.