Question

1. invading microorganisms sometimes enter the body and threaten its health. how does the body protect itself from these invaders?

a) the respiratory system removes invaders from the blood.
b) the immune system collects and stores the invading organisms.
c) the respiratory system surrounds the invaders with carbon dioxide.
d) the immune system kills or disables the invading organisms.

1. the respiratory system takes oxygen into the human body and expels carbon dioxide. which body system interacts with the respiratory system to transport these gases to and from the various parts of the body?

a) the digestive system
b) the excretory system
c) the cardiovascular system
d) the nervous system

Explanation:

• Question 6:
• The immune system is responsible for protecting the body from invaders. It does this by killing or disabling the invading organisms.
• The respiratory system's main function is gas exchange (taking in oxygen and expelling carbon dioxide), not removing invaders from the blood or surrounding invaders with carbon dioxide.
• The immune system does not collect and store invaders; it eliminates them.
• Question 7:
• The cardiovascular system (which includes the heart and blood vessels) interacts with the respiratory system.
• Oxygen taken in by the respiratory system enters the blood in the lungs and is then transported by the cardiovascular system to all parts of the body. Carbon dioxide from the body cells is transported by the cardiovascular system back to the lungs (respiratory system) to be exhaled.
• The digestive system is for breaking down food and absorbing nutrients.
• The excretory system is mainly for removing waste products (other than carbon dioxide).
• The nervous system is for transmitting signals and controlling body functions, not for gas transport.

Answer:

1. D. The immune system kills or disables the invading organisms.
2. C. The cardiovascular system.