What body parts work together to from the digestive system?

In this experiment, the was intentionally manipulated. it is the independent variable. the dependent variables that were measured were the

Give an example of a trait that is controlled by more than one gene.

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?