Which of the following is an example of a free-running cycle? a) A dog that sleeps all night and stays awake all day
b) A cat that wakes at night and sleeps during the day
c) A dog that sleeps and wakes at various times of the day and night
d) A baby that sleeps four hours at a time, then awakens to eat

The rate at which molecules water and oxygen can enter a cell is determined by the-

Land conservation is a worldwide priority. there are several methods to prevent the loss of land due to a variety of reasons. which method is not a way to conserve land? a) sea walls b) rainwater harvesting c) limits on clear cuts of forests d) cut and burn methods of clearing land

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.