Which of the following are part of the body’s first line of defense against pathogens?

a. white blood cells

b. red blood cells

c. lymph nodes

d. mucous membranes

All living organisms are composed of a. only one cell. b. at least 100 cells. c. at least three cells. d. one or more cells.

How is the national wildlife refuge system similar to the pacific region coastal program? a. both programs are concerned with providing habitats for wildlife b. both programs are primarily concerned with preserving fish species c. both programs have set aside 150 million acres of land d. both programs are under the u.s. fish and wildlife service

What would happen if the krill were removed from the food web