Question

Meristem that is parallel to the longitudinal axis of the plant is
(a) Procambium
(b) Intercalary meristem
(c) Phellogen
(d) Apical meristem

Answer 1

Hint: Meristem is the tissues that are responsible for the growth of the plant- both in length and girth. There are many different types of meristem present in different parts of stem and root where growth occurs.

Complete step by step answer:
Phellogen is the meristem that is parallel to the longitudinal axis of the plant which is responsible for the development of the periderm. There are cells that grow inwards from there called phelloderm whereas the cells develop outward are known as phellem.

Additional Information: Meristems are tissues of living cells with no Intercellular space and these cells divide actively to form different structures in the plant body. These tissues help in the increase of length and girth of the plant.
Here's an explanation for each term:
Phellogen: Also known popularly as cork cambium. This is a layer of meristematic cells which develops the periderm and is found in many vascular plants as a part of the epidermis.
Procambium: It consists of meristematic tissue and helps to provide the primary tissues of the system of the vascular plants. They produce new vascular tissue in mature stems and roots.
Intercalary meristem: It is the meristematic tissue responsible for the growth in length in the middle position. The cells of this tissue divide mitotically in the stem at the base of nodes and leaf blades.
Apical meristem: These are found in the root tips and tips of new shoots and leaves and it is a type of meristem that can differentiate into different cell types.
So, the correct answer is ‘Phellogen’.

Note: The different types of meristem found in plants based on origin are promeristem, primary meristem, and secondary meristem. Based on occurrence there are other 3 types of meristem namely apical, Intercalary and lateral meristem. They are divided into 3 types based on the functions as well. These are protoderm, procambium, and ground meristem.