Following features belong to

a) Cells are generally isodiametric. They may be spherical, oval, round, polygonal or elongated in shape

b) Cells have thin wall and are made up of cellulose

c) Cells may be closely packed or may have intercellular spaces

d) Tissues perform various kinds of functions like photosynthesis, storage and secretion

Parenchyma is a simple living tissue. The term parenchyma was given by Grew. It is most abundantly present in the primary plant body. Cells of parenchyma are of various shapes and sizes which is dependent on the function. Usually its cells are spherical, oval, polyhedral or isodiametric. Cell wall is thin with uniform thickness. It usually has primary wall consisting of cellulose and pectin with plasmodesmata. The parenchyma performs various functions like  photosynthesis, storage and secretion .