What is responsible for identifying foreign invaders and remains in the system for a long period of time.
a. red blood cells
b. axons
c. antigens
d. lymph nodes

Which of these statements best describes the st. lawrence seaway? the st. lawrence seaway connects the st. lawrence river with the arctic ocean. the st. lawrence seaway provides an important trading route between the u.s. and mexico. the st. lawrence seaway provides an important trading route for the u.s, but has little value for canada. the st. lawrence seaway connects the great lakes, the st. lawrence river, and the atlantic ocean.

Which of the following is a difference between active transport and facilitated diffusion? view available hint(s)which of the following is a difference between active transport and facilitated diffusion? facilitated diffusion can move solutes against a concentration gradient, and active transport cannot.active transport involves transport proteins, and facilitated diffusion does not.facilitated diffusion involves transport proteins, and active transport does not.active transport requires the expenditure of cellular energy, and facilitated diffusion does not.

18. which statement about cancer is true?