What did the early fossil discoveries described demonstrate?

Identify any four organelles that should be present in the eukaryotic organism and describe the function of each organelle

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?

Which particle controls what element an atom is?