Botany - B.E. Yakubenko 2017

Part One. Plant Anatomy and Morphology
Chapter I. Cytology
1.2. Cell size and shape. Structure of eukaryotic and prokaryotic cells

Plant Cells vary significantly in size and shape, which largely depends on their specific Functions and Location within the plant. Cells subjected to pressure from all sides tend to be polygonal, while others may be cylindrical, stellate, or spherical. Their dimensions range from a few dozen nanometers to a few centimeters in exceptional cases. The majority of cells are microscopic and can only be seen under a Microscope. Bacterial cells are the smallest. Cells of angiosperms are larger, typically ranging from 0,01 mm to 0,1 mm. Macroscopic structures can be observed in the pulp cells of tomato and watermelon fruits, as well as in the fibers of certain fiber-yielding plants. The largest dimensions are found in flax bast fibers (20—40 mm) and ramie fibers (up to 200 mm). Meanwhile, the cells of certain Algae can reach up to 15 cm in length, such as those in multicellular charophyte algae.

The vast majority of plant cells maintain a constant shape. Despite their diverse forms, plant cells are broadly classified into two main types: parenchymatous, where the length and width of The Cell are nearly equal, and prosenchymatous, where the length significantly exceeds the width. Parenchymatous cells predominantly perform photosynthetic, assimilative, and nutrient-storage functions. Prosenchymatous cells typically serve conducting and mechanical roles, very often after the living Contents of the cell have died.

Cells may possess a Nucleus, in which case they are termed eukaryotic; if a cell lacks a nucleus, it is referred to as prokaryotic. Plant cells are invariably eukaryotic, whereas only Bacteria and cyanobacteria (blue-green algae) possess Prokaryotic Cells.