How do frogs and toads, as well as salamanders, typically protect themselves from predators? by injecting venom into the predator using teeth
by crawling or hopping to a safe place
by squeezing the predator to suffocate it
O by rolling over and pretending to be dead

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.

Which of the following describes what an activator an enhancer are