What scientific breakthrough was made in the 1940s and 1950s? A: DNA research

B: paleontology

C: cell theory

D: natural selection

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine