a. prevents hemophilia
b. carries oxygen
c. creates blood clots
d. fights infections
Which statement is not true of cilia in the respiratory tract?
a. They are thin structures that resemble hairs.
b. They help clean the respiratory system.
c. They move mucus from the bronchi to the pharynx.
d. They close the windpipe opening when swallowing.
Which system supports the body and protects organs?
Which part of the skin contains blood vessels, nerves, and glands?
c. fatty layer
Your body’s metabolism is regulated by _____.
d. adipose cells
How do muscles work in antagonistic pairs?
a. Both muscles always contract at the same time.
b. Each muscle is attached to a different ligament.
c. When one muscle pulls, the other muscle relaxes.
d. The muscles alternate, producing wavelike contractions.
Which action removes carbon dioxide from the body?
c, d, a, a, b, c, b