Question

Meristematic cells are characterized by
(a)Thin cellulosic walls
(b)Dense protoplasm
(c)Prominent nuclei
(d)All the above

Answer 1

Hint: Meristems can enlarge, stretch as well as it can differentiate into all other cell types (totipotent cells). Meristematic cells are undifferentiated cells.

Complete answer:
The meristematic cells are in a constant division phase. Meristematic tissues are commonly observed in the growing plant parts. Meristematic tissues can divide throughout the lifetime of a plant. The main characteristics of the meristematic tissues are:
-They possess a thin cell wall made of cellulose.
-Intracellular space is absent.
-The cytoplasm is dense and has a prominent nucleus.
-Cells can be oval, round, polygonal, rectangular.
-Vacuoles are absent or in some cases, they might have multiple tiny vacuoles.
-The cells will have a high rate of metabolism.

Additional Information:
Depending upon the origin, location, and function, the meristematic cells are divided into various types.

Based on the origin
-Promeristem: It arises from the embryo. The primary meristem develops from the Promeristem. Example: root and the shoot tip.
-Primary meristem: It develops from the primary meristem and can divide continuously. The permanent tissues will be formed from the primary meristem.
-Secondary meristem: The secondary meristem arises from the primary meristem and the permanent tissues will be formed from them.

Based on the location
-Apical meristem: They are observed in the tips of both the roots as well as the shoot. It is divided into promeristem and will have protoderm, procambium as well as ground meristem.
-Intercalary meristem: They are located in the leaves as well as in the internodes. It will increase the length of the internode. Furthermore, it is an apical meristem that will add the height to the plant. Example: grass.
-Lateral meristem: Present in the stems, roots and will increase the plant thickness. Vascular and cork cambium forms the lateral meristem.

Based on the function
-Protoderm: It is the outermost tissue and the protoderm will form the epidermis. It prevents the plants from mechanical shock.
-Procambium: It will form the xylem and the phloem and it is the innermost tissue. Xylem and phloem will help in the transport of water to different plant parts.
-Ground meristem: It will develop into the cortex, pericycle, and the pith.

So, the correct answer is ‘All the above’.

Note: The meristematic cells as already stated can differentiate into various other cell types. These differentiated cells will lose the totipotent properties and therefore they cannot differentiate into other cell types.