What is the immune system?

A. The group of cells and organs that protect the body from disease.

B. A group of cells that undergoes apoptosis to protect the body.

C. A group of organelles that digest particles that invade the cells.

D. The group of cells and organs that turn food into energy for the body.

Cpr, or cardiopulmonary resuscitation, is a first-aid technique to save lives. it involves compressions of the patient's chest cavity. which description is the best description of the functions of chest compressions in cpr? chest compressions are done to pump the heart. chest compressions are done to strengthen the rib bones. chest compressions increase carbon dioxide inhalation. chest compressions allow the patient's muscles to wake up.

The two tubes contain bromothymol blue. after 24 hours, what will the color of the water be in tube b? a. green (it won't change) b. yellow c. blue d. colorless (clear)

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.