AAT Bioquest

What are the primary types of cells?

Posted April 28, 2022


There are two primary types of cells – prokaryotic and eukaryotic. 

Prokaryotic Cells

Prokaryotic cells are smaller and simpler than their eukaryotic counterparts. One of the most notable differences between the two is the absence of a true nucleus in prokaryotic cells. Instead, these cells have a nucleoid region in the cytoplasm. Another difference between the two is the lack of any type of organelles within the cell. The innermost region of prokaryotic cells is the cytoplasmic region, which contains a single circular chromosome and ribosomes. This region is enclosed by a cell envelope, which is made up of a plasma membrane covered by a cell wall. The outermost region consists of flagella and pili, which project outward from the cell’s surface and are involved in movement and communication between cells. Cell division occurs through simple division known as binary fission. Bacteria and archaea are the only two types of organisms that have prokaryotic cells. They are also called prokaryotes. 

Eukaryotic Cells 

Eukaryotic cells are larger and more complex than prokaryotic cells. Like prokaryotic cells, they also have an innermost cytoplasmic region enclosed by an outer plasma membrane. In addition, they also have a membrane-bound nucleus or a true nucleus, which houses multiple rod-shaped chromosomes as well as numerous membrane-bound organelles including the Golgi apparatus, endoplasmic reticulum, mitochondria, ribosomes, and chloroplasts. Each of these organelles have specialized roles, allowing different functions to be compartmentalized in specific areas in the cell. The type and number of organelles may vary slightly depending on whether the cell is a fungi, plant or animal. Cell division occurs through mitosis (fission or budding) or meiosis. All types of plants, animals, and fungi are made up of eukaryotic cells. These organisms are known as eukaryotes. 

Additional resources

Guidelines for a Morphometric Analysis of Prokaryotic and Eukaryotic Cells by Scanning Electron Microscopy

Cell Meter™ Colorimetric WST-8 Cell Quantification Kit