Absolute magnitude . a) is usually the same as apparent magnitude
b) is how bright a star appears from Earth
c) depends on luminosity and distance
d) is a measure of a star's actual brightness

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?