Question

Which of the following is a secondary meristem?
a. Protoderm
b. Procambium
c. Cork cambium
d. All of the above

Answer 1

secondary meristem is a type of tissue responsible for secondary growth such as growth in thickness, where it is different from primary growth tissue where there is growth in height or length

**Complete answer :**
Cork cambium is a tissue found in many plants .

It is found as a part of epidermis of plants
It is usually found in between the primary phloem and cork
It is responsible for the lateral growth of the plant.
It is usually found in dicot plants as secondary growth is commonly seen in them.
Both vascular cambium and cork cambium is considered as secondary meristems
Where vascular cambium is produced in stem and roots, where they form a woody tissue.
The cork cambium usually forms a bark tissue.
Secondary phloem is also a part of the bark of the woody plant, as we know secondary phloem usually develops from secondary cambium.
They usually arises as a concentric layer
This cork cambium is also called as phellam which usually forms outside the stem
Suberin is the dead material usually found in the phellam , it helps the stem from water loss and as well as from mechanical damage.
As the tree grows ,the bark layer increases which increases the circumference of the tree.
As the plants develops additional cork cambium arises from the secondary phloem
Where as other options such as procambium and Protoderm come under primary meristems

From the above explanation the answer is cork cambium.

Note: In dicots there will be secondary growth, where the secondary meristem arise, it is a permanent tissue which is usually arise and form the secondary tissue such as cork cambium and vascular cambium