What is heart wood made
of?
A. the center rings that are dark and no
longer work as they are filled with resin this is answer
B. the outer layer of rings that are
rough and have a waxy protective
coating
C. the lighter rings of a tree that are
the living tissue

answer: the center rings that are dark and no longer work as they are filled with resin heartwood, also called duramen, dead, central wood of trees. Its cells usually contain tannins or other substances that make it dark in colour and sometimes aromatic. Heartwood is mechanically strong, resistant to decay, and less easily penetrated by wood-preservative chemicals than other types of wood.