Multiple choice

The walls of xylem vessels are made up of _________________.

  1. cellulose

  2. lignin

  3. glucose

  4. both (1) and (2)

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Xylem vessel walls contain both cellulose for structural strength and lignin for waterproofing and rigidity. This combination creates strong, impermeable tubes for water transport under tension.