MDCAT Biology MCQ #1661

A structural analysis of a xylem vessel reveals a thick cell wall layer containing cellulose, hemicellulose, and significant amounts of lignin.

MDCAT Biology MCQ #1661

  1. Question 1

    Q1. A structural analysis of a xylem vessel reveals a thick cell wall layer containing cellulose, hemicellulose, and significant amounts of lignin.

    • A) Primary wall
    • B) Secondary wall
    • C) Middle lamella
    • D) Plasmodesmata

    Answer: Secondary wall

    Explanation: Secondary cell walls contain lignin for strength; primary walls are tempting but are mainly composed of cellulose and pectin.