Science: The Immune System
How the body defends itself from germs
Science: The Immune System
How the body defends itself from germs
Biology - Grade 6-8
- 1
What is the main job of the immune system in the human body?
Think about what happens when bacteria or viruses enter the body.
The main job of the immune system is to protect the body from harmful germs and other substances that can cause illness. - 2
Name two types of germs that can make people sick, and explain how they are different.
Two types of germs are bacteria and viruses. Bacteria are living single-celled organisms, while viruses are smaller particles that must enter living cells to reproduce. - 3
How does the skin help the immune system defend the body?
Think about the body's first line of defense.
The skin helps the immune system by acting as a barrier that blocks many germs from entering the body. - 4
What role do white blood cells play in the immune system?
White blood cells help the immune system by finding, attacking, and destroying harmful germs and infected cells. - 5
Explain what inflammation is and why it can be helpful when you get a cut.
Think about why a cut might become red or swollen.
Inflammation is the body's response to injury or infection that can cause redness, swelling, heat, and pain. It is helpful because it brings immune cells to the injured area to fight germs and begin healing. - 6
What is a pathogen, and how is it related to disease?
A pathogen is a disease-causing germ or agent, such as a virus, bacterium, fungus, or parasite. Pathogens can make people sick when they enter the body and multiply or damage cells. - 7
Describe how antibodies help the body fight infection.
Think about special proteins that recognize certain invaders.
Antibodies are proteins made by the immune system that attach to specific germs. They help by marking germs for destruction or blocking them from harming cells. - 8
Why do vaccines help protect people from some diseases?
Vaccines help protect people because they train the immune system to recognize and respond to specific pathogens before a person gets seriously sick. - 9
A student says, "Antibiotics can cure the flu because the flu is caused by bacteria." Explain what is wrong with this statement.
Decide whether the flu is caused by bacteria or a virus.
This statement is wrong because the flu is caused by a virus, not bacteria. Antibiotics work against bacterial infections, but they do not kill viruses like the flu. - 10
How do fever and mucus help the body defend itself during illness?
Fever can slow the growth of some pathogens and help the immune system work more effectively. Mucus helps trap germs so they can be removed from the body. - 11
Compare innate immunity and adaptive immunity in one or two sentences.
One type is general and immediate, and the other is specific and learned.
Innate immunity is the body's fast, general defense against many kinds of threats. Adaptive immunity is a more specific response that targets particular pathogens and can create memory for future protection. - 12
List two healthy habits that help keep the immune system working well, and explain why each habit matters.
Two healthy habits are getting enough sleep and washing hands regularly. Sleep helps the body repair itself and support immune function, while handwashing removes germs before they can spread or enter the body.