Groundwater . forms when precipitation seeps into the soil exists above the earth's surface is impossible to pollute is not a usable water source for humans

This is the amino acid cysteine. circle the amine group, put a box aroundthe carboxylic acid group and use a different colored pencil/pen to circle the sidechain (r group). h o | ||nh2— c- c-oh | ch2 | sh

The similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between organisms in both locations?

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important