Viruses, bacteria, fungi, and parasites may infect the human body and interfere with normal body functions. A person can catch a cold many times because there are many varieties of cold viruses that cause similar symptoms.
Learning Goal 4
White blood cells engulf invaders or produce antibodies that attack them or mark them for killing by other white cells. The antibodies produced will remain and can fight off subsequent invaders of the same kind.
Learning Goal 6
Specific kinds of germs cause specific diseases.
Learning Goal 7
Vaccines induce the body to build immunity to a disease without actually causing the disease itself.
For Grades: 9-12
Learning Goal 3a
New medical techniques, efficient health care delivery systems, improved diet and sanitation, and a fuller understanding of the nature of health and disease give today's human beings a better chance of staying healthy than their ancestors had.