Which of the following statements correctly describes the role of white blood cells in the human immune system?

Which best describes red blood cells? a. they are colorless b. they protect against disease-carrying microorganisms c. they transport oxygen throughout the body d. they aid in blood clotting

What does it mean for a cell membrane to be selectively permable

Microorganisms are involved in each of the following processes excepta. smog production.b. food production.c. infection.d. o2 production.e. decomposition of organic material.