Question

The bark of tree commonly comprises
A. All the tissues outside the vascular cambium
B. All the tissues outside the cork cambium
C. Only the cork
D. The cork and secondary cortex

Answer 1

Hint: Bark commonly constitutes dead cells present on the outer surface of stems and roots. The inner bark consists of living tissue.

Complete answer:
To answer this solution, we need to know the tissues that make up bark. Bark is found on the outermost surface of woody plants. It is made up of several tissues that include secondary phloem, cork cambium and cork.
Now, let us find the solution from the given options-
A) The vascular cambium is involved in the secondary growth of plants and lies between xylem and phloem. Active division adds layers of secondary phloem and xylem on the outer and inner layers of the stem. As the layers are pushed outward, they compress and the cells die. All the layers of tissue outside the vascular cambium constitute bark- secondary phloem, cork and cork cambium.
B) The cork cambium is the meristem that develops from parenchyma cells in the remaining cortex. It produces the outer layer of cork and lies outside the vascular cambium.
C) Cork is produced by the cork cambium and forms part of the outer bark. The cork cells are dead cells and serve to provide protection against pathogens and damage to the internal cells.
D) The secondary cortex is part of the inner bark. It consists of living tissues and is formed on the inner side of cork cambium. As it lies outside the vascular cambium, it is considered a part of bark.

So, the correct answer is option A i.e., All the tissues outside the vascular cambium.

Note: Essentially, bark comprises all the tissues outside the wood of a tree. It forms the outer covering of trees and helps to protect against loss of moisture.