Question

Explain the formation of bark of a tree. How does it act as protective tissue ?

CBSE Class IX Science SA 2 (3 Marks)

Answer 1

As plants grow older, the outer protective tissue undergoes certain changes. A strip of secondary meristem replaces the epidermis of the stem. Cells on the outside are cut off from this layer. This forms the several layer thick cork or bark.

Plants also have a chemical called suberin in their wall that makes them impervious to gases and
water.