What roles does mucus have in the immune system? O It traps germs so they do not get into the body.
O It helps people build immunity to diseases.
O It builds up defenses and antibodies against a disease.
O It makes antibodies to help humans fight disease.

How is health different for most people in this country today from what it was for people born in 1900? a. people have a shorter life span. b. people today work harder to survive. c. people today live in poorer sanitary conditions. d. people today can focus less on day-to-day survival and more quality of life.

Meg is moderately active and completes 30minutes of daily activity above the baseline level. based on the chart, which activity will not increase megs physical fitness?

Check all that occur during ventricular systole. a. the av valves open to allow blood to enter the ventricles from the atria. b. the av valves open to allow blood to enter the ventricles from the atria. c. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. d. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. e. the semilunar valves open to allow blood to flow into the large arteries. f. the semilunar valves open to allow blood to flow into the large arteries. g. the av valves close to prevent backflow of blood into the atria.