Question Detail
Question
Waste products accumulated in the older xylem of plants play a major role in the formation of what?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Page 41 states, 'Some waste products accumulate in the older xylem; and play a major role in the formation of heartwood.' This is also visually represented on page 42.
Hint
Think about the central, usually darker, part of a tree trunk.