What is the importance of corals forming a reef colony?

What do heterotrophic cells need to survive?

Always use significant figure rules. remember that these rules apply to all numbers that are measurements. a car travels 6 miles north, 3 miles east, and then 2 miles south. what is the distance traveled? a.7 b.11

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?