5. Each osteon has a
central canal. What
three things are found
within this canal?

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

What is one reason why transpiration is important in plants? question 19 options: it produces food from the sugar in the plant cells. it enables the flow of water out of the plant. it produces carbon dioxide in the leaves of the plant.

Compare the shapes of the bones of the human skull with the shapes of the bones of the human leg. how do the shapes differ? why are the shapes important?