1. Which of the following effects would you expect if red blood cells were shaped like neurons?

They would not be able to move as easily through capillaries. ****
They would more easily carry out gas exchange in the alveoli.
They would not need to be transported through the body.
They would become more effective at picking up urea discarded by body cells.

2. Which of the following is not a function of the skeletal system?

supports the body
works with other body systems to allow movement
manufactures new blood cells ****
sends signals to the brain

3. Which of the following body systems are involved in the first line of defense of
the immune system against infection?

integumentary, digestive, respiratory ****
nervous, circulatory, skeletal
muscular, endocrine, urinary
urinary, skeletal, integumentary

4. Which of the following sets of structures would be involved in ridding the body of
unwanted urea?

sensory neuron, interneuron, spinal cord
alveoli, atrium, cilia
capillary, nephron, ureter *****
brain, esophagus, small intestine

5. An infectious disease is a disease that

is caught because the weather turns cold.
is caused by pathogens.****
can be spread only by bacteria.
cannot be cured.

6. Which of the following statements is true regarding infectious agents?

Infectious agents are all too small to be seen without a microscope, and none can be classified as living.
All infectious agents are living because they are all classified as microorganisms.
Of all the infectious agents, only viruses are considered living because they actively inject their DNA or RNA into host cells. *****
Viruses cannot be treated with antibiotics because they are not living organisms.