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PLANT TISSUES AND CELLS

Parenchyma

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Organization of The Plant
Plant Tissue Systems
Simple Tissues
Parenchyma
Collenchyma
Sclerenchyma
Glossary

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Parenchyma cell

Parenchyma cell are the main representative of the ground tissues system found in all plant organ. The cells consist of isodiametric, thin walled and equally expanded cells. Parenchyma cells are variable in their morphology and carry on a variety of function in relation to their position in the plant. Living parenchyma cells found in all plant organs perform most of the metabolic function of the plant,synthesizing and storing various organic products. Most parenchyma cells retain the ability to divide and differentiate into other types of plant cells under special condition.

Meristematic Parenchyma

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Meristematic Parenchyma

Meristematic cells are parenchyma cells that consist of a group of cells which remain in continuous state of division or they retain their power of division. They composed of immature cells with no intercellular spaces. Meristematic parenchyma contain abundant cytoplasm with one or more nuclei. The vacuoles are small or absent.

Storage Parenchyma

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Storage Parenchyma

Storage parenchyma is specialized as large water storage tissue in many succulent and xerophytic plants with greatly expanded vacuole. The cells are chlorophyll-free and thin-walled. In potatoes tuber and grain for example, the parenchyma acts as a special storage tissue to store food material.
 
 

Transport Parenchyma

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Transport Parenchyma

Transfer parenchyma is also known as transfer cell. The cells have one or several walls that are highly modified, having many folds, ridges and papillae in their inner face to increase the absorption or secretion surface. The transfer cells are always characterized by wall ingrowths. These consist of a specialized form of unlignified secondary cell wall. The plasma membrane of the cell follows the outline of these wall ingrowths. As a consequence, the area of the plasma membrane is greatly increased (more than 20 times than of an ordinary parenchyma cell) facilitating the increase of absorption or secretion of solutes by the protoplast.

Branched Parenchyma

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Branced Parenchyma

Parenchyma cells can be highly branched. These are from the stem of a sedge that contains lots of intercellular spaces (air spaces) which is called aerenchyma. Aerenchyma is typically found in hydrophytes (aquatic) plants and is functioning in keep the buoyancy of the plants and physical support. The air spaces also facilitate in the exchanging of gases.
 
 

Mesophyll Parenchyma

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Mesophyll Parenchyma

When parenchyma are exposed to light they develop chloroplast in them, such tissues is known as chlorenchyma. The cells touch each other as little as possible to free maximum surface for carbon dioxide absorption. A large central vacuoles press the chloroplast into a uniform layer next to the wall to prevent self-shading and placing the chloroplast at the site of carbon dioxide absorption. This type of parenchyma cells are found most in leaves and stem which can be distinguish between palisade and spongy mesophyll.

Folded Parenchyma

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Folded Parenchyma

Folded parenchyma is the parenchyma cells with invagination or folds around their edge, which usually a characteristics of some gymnosperm for example the pine leaf.

Additional Information :

Parenchyma

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