Question

in our immune system, white blood cells assist in fighting off infections. as we become exposed to bacteria, they enter our body through varying means. part a which statement best describes the action of white blood cells as they encounter a foreign invader, such as bacterial cells? diffusion allows the white blood cells to remove the bacterial invaders by moving them across the membrane using embedded proteins. bacteria are moved out of the cell in order to balance the concentration gradient on both sides of the cell membrane. the bacterial cell fuses with a vesicle to be removed from the cell through the process of exocytosis. the cell membrane engulfs the bacterial cell and destroys it through the process of endocytosis. unanswered

Explanation:

White blood cells use the process of endocytosis to engulf and destroy foreign invaders like bacteria. Endocytosis is when the cell membrane surrounds and takes in a particle. Exocytosis is for releasing substances from the cell, not for taking in bacteria. Diffusion is the movement of substances down a concentration gradient and is not how white - blood cells primarily deal with bacteria. Bacteria moving out of the cell to balance concentration is not relevant to white - blood cells fighting them.

Answer:

The cell membrane engulfs the bacterial cell and destroys it through the process of endocytosis.