What is the outermost protective layer of woody stems and roots primarily composed of cork cells?

What is the outermost protective layer of woody stems and roots primarily composed of cork cells?

• A. Inner Bark
• B. Outer Bark
• C. Xylem
• D. Phloem

Answer: (B)

In woody plants, the outermost protective covering is the bark, formed by the periderm. The outer portion of the periderm is cork (phellem) produced by the cork cambium, and these cork cells become dead and tightly packed to form a tough, waterproof barrier. This cork layer is what protects the underlying tissues from water loss, pathogens, and physical damage as the plant grows outward. Inner bark consists of phloem and related tissues involved in transport, not the outermost protection, xylem is the inner wood tissue, and phloem is an internal transport tissue. So the layer that is mainly cork cells and sits as the outer protective cover is Outer Bark.

In woody plants, the outermost protective covering is the bark, formed by the periderm. The outer portion of the periderm is cork (phellem) produced by the cork cambium, and these cork cells become dead and tightly packed to form a tough, waterproof barrier. This cork layer is what protects the underlying tissues from water loss, pathogens, and physical damage as the plant grows outward. Inner bark consists of phloem and related tissues involved in transport, not the outermost protection, xylem is the inner wood tissue, and phloem is an internal transport tissue. So the layer that is mainly cork cells and sits as the outer protective cover is Outer Bark.