Paleontologists have discovered ancient prokaryotic fossils dated at over 3.5 billion years old. these fossils resemble prokaryotes that are capable of living in extreme conditions such as high temperature and salinity. what domain do these prokaryotes belong to

Which organelle breaks down sugar molecules that supply energy to the cell ?

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 is one way in which organisms such as clown fish and sea turtles are able to overcome the many dangers that their offspring encounter and ensure that their species population numbers stay relatively steady