question_answer 80)

  (a) Differentiate between meristematic and permanent tissues in plants. (b) Define the process of differentiation. (c) Name any two simple and two complex permanent tissues in plants.    

Answer:

  (a) The basic differences between meristematic and permanent tissues of plants are tabulated below

Meristematic tissue	Permanent tissue
Its component cells are living, small, spherical or polygonal and un-differentiated	Its components cells may be living or dead. They are large, differentiated with different shapes.
Cytoplasm is dense and vacuoles are nearly absent as they are metabolically active.	Large central vacuole occurs in living permanent cells as, they are less metabolically active.
Intercellular spaces are absent.	Intercellular spaces are often present.
Cell wall of its cells is thin and elastic.	Cell wall of its cells may either thin or thick.
Nucleus of each cell of this tissue is large and prominent.	Nucleus of each cell of this tissue is less conspicuous.
Its cells grow and divide regularly.	Its cells do not normally divide.
It is a simple tissue.	It can be simple, complex or specialized,
Cell organelles of its cells are simple	Cell organelles of its cells are well developed.
Cell of this tissue do not contain crystals and other inclusions.	Cells of this tissue possess crystals and other inclusions.
It provides growth to the plant.	It provides protection. Support, conduction photosynthesis, storage, etc.

(b) Cells derived from the division of meristematic tissues take up specific roles and gradually lose their ability to divide. Thus, they form permanent tissue. The process by which the cells divide meristematically to take a permanent shape, size and function is called differentiation. (c) Two simple permanent tissue in plants are parenchyma and collenchymas while two complex permanent tissue in plants are xylem and phloem.