Complete the following chart:

AcademicBiologyNCERTClass 9

Correct Answer:


Parenchyma cells originate from the ground and protoderm meristems. These are living and unspecialized cells. They are known as unspecialized because these cells although are living differentiated cells and have lost the capacity to further divide, these cells regain the capacity of division under certain circumstances. 

Fully differentiated parenchyma cells give rise to interfascicular and cork cambium during secondary growth by the process of differentiation. Parenchyma forms the "filler" tissue in the soft parts of plants and is usually present in the cortex, pericycle, pith, and medullary rays in the primary stem and root. Thus, they are known for healing and repair mechanisms, and food storage.

Parenchyma tissues are present in the pith of the roots and stems. When it contains chlorophyll, it is called chlorenchyma, found in green leaves. In aquatic plants, parenchyma contains large air cavities and helps them to float. Such a type of parenchyma is called aerenchyma.

Sclerenchyma cells are elongated, dead cells with lignin deposits in their cell wall. They have no intercellular gaps. It is found in the covering of seeds and nuts, around the vascular tissues in stems, and the veins of leaves. Its main function is to provide strength to the plant.

Phloem is a living tissue in vascular plants. Its function is to conduct soluble organic compounds synthesized during photosynthesis from the leaves to downwards. The phloem consists of companion cells, sieve tubes, phloem fibers, and phloem parenchyma.

Updated on 10-Oct-2022 12:47:33