Compare the productivity of terrestrial and aquatic ecosystems against the percent of Earth’s surface area they occupy.

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from

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.

What does the number 18.9984 represent in the image?