are produced by theto destroy specific foreign invaders in the body.

What are some things that limit population growth?

What is the identity of the planets?

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?