Question

Which of the following plant tissues is not a simple permanent tissue?
A. Xylem
B. Collenchyma
C. Sclerenchyma
D. Parenchyma

Answer 1

Hint: There are three main tissue systems in a plant body. They are epidermal, ground tissue, and vascular tissue. Another classification is based on the ability to divide, that is, into permanent and meristematic tissues.

Complete answer:
Permanent tissues are those tissues that have lost the ability to divide further. And simple tissues are those which are composed of a single type of cell. In xylem tissue, it is composed of four different kinds of cells, they are tracheids, xylem vessels, xylem fibers, and xylem parenchyma. Thus it is a complex tissue. The xylem parenchyma are living cells, thus it cannot be considered as permanent tissue.
Considering the other given options:
Collenchyma is simple tissue since it consists of only one type of cells, that is the collenchyma cells. The collenchyma is living cells, with actively dividing protoplasm. Hence it is not a permanent tissue. Collenchyma is a simple tissue but not permanent. Thus it is not the appropriate option.
Sclerenchyma is lignified cells, with no protoplasm. They are permanent tissue but are simple since it consists of only a single type of cell. Thus it is not an appropriate answer.
Parenchyma is not permanent tissue, since they are actively dividing, and has abundant protoplasm. But these are simple tissues since they have just one cell type in the tissue. Thus it is not the appropriate option.
Therefore from the above-given options, the most appropriate answer is A. That is, Xylem is not a simple permanent tissue.

Note: The other type of complex tissue is the phloem tissue, which is involved in the translocation of organic nutrients. The different components of the phloem are the Sieve tube, companion cells, phloem parenchyma, and phloem fibers.