Explain the structure of parenchyma. What are its major types?
Parenchyma. It is the basic or fundamental tissue found in plants. Parenchyma acts as a packing tissue and therefore, it is found in between other tissues. Parenchyma tissue cells store starch, proteins, minerals etc.
i. These are thin walled, circular or polygonal and isodiametric, i.e., having similar sides.
ii. They are living and consists of cytoplasm and a nucleus.
iii. There are many small or a single big central vacuole.
iv. They may not have intercellular space or may have intercellular spaces.
Some parenchymatous cells have pigmented chromoplats. The most important are the cells which contain a number of chloroplasts and the tissue is green, it is known as chlorenchyma.
Some non-green chromoplasts provide different colours to flowers and fruits.
Sometimes the cells contain big air spaces in between them. Such tissue is known as aerenchyma. On the other hand some tissues are green, containing many air spaces then it is called spongy tissue.
