Which is most likely to be part of an ionic bond
a. an atom with no valence electron
b. an atom with one valence electron
c. an atom with two valence electrons
d. an atom with three valence electrons.

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms? a) male gametophyteb) female gametophytec) male sporophyted) female sporophyte

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.

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.