52 One of the trends observed across numerous kingdoms is toward differentiation and specialization of cells. When you studied the unicellular green algae, you discovered that these single cells have to accomplish all of the basic functions of life. Over the course of evolution, multicellular organisms demonstrate a greater specialization in cells and subsequently an increased diversity of function. In contrast to unicellular green algae, plants evolved numerous specialized cells, such as those for photosynthesis, those for transport of organic and inorganic nutrients, and those for reproduction. Plant cells may fall into one of three general cell types. Each cell type is based on both the type of cell wall it possesses and the cell's function. The three cell types are described below. 1. Parenchyma cells - are unspecialized cells (that is they are NOT differentiated) that are characteristically thin walled and many sided. They make up the bulk of the plant body and perform virtually all the metabolic activities
This is the end of the preview.
access the rest of the document.