Reproduction

Bacteria and archaea reproduce through asexual reproduction known as binary fission. Binary fission is an asexual mode of reproduction. During binary fission, the genomic DNA undergoes replication and the original cell is divided into two identical cells. Due to binary fission, all organisms in a colony are genetically equivalent (Figure 4). The process begins with DNA replication followed by DNA segregation, division site selection, invagination of the cell envelope and synthesis of new cell wall which are tightly controlled by cellular proteins. A key component of this division is the protein FtsZ which assemble into a ring-like structure at the center of a cell. Other components of the division apparatus then assemble at the FtsZ ring. This machinery is positioned so that division splits the cytoplasm and does not damage DNA in the process. As division occurs, the cytoplasm is cleaved in two, and new cell wall is synthesized.

Figure 4: Binary fission in prokaryotes

Products/Application

Prokaryotes help manufacture yogurt, cheese, sour cream, antibiotics etc. They are the store house of many industrially important enzymes such as lipases, proteases, amylases which find use in detergent, paper and leather industries.

Eukaryote

A eukaryotic cell consists of membrane bound organelles. They belong to the taxa Eukaryota. All species of large complex organisms are eukaryotes, including animals, plants and fungi and most species of protist microorganisms. Eukaryotes appear to be monophyletic (organisms that form a clade) and make up one of the three domains of life. The two other domains, Bacteria and Archaea, are prokaryotes and have none of the above features. Eukaryotes represent a tiny minority of all living things; even in a human body there are 10 times more microbes than human cells. However, due to their much larger size their collective worldwide biomass is estimated at about equal to that of prokaryotes. Unlike prokaryotes, eukaryotic genome is enclosed in the nucleus surrounded by the nuclear membrane.  Other then the nucleus many membrane bound organelles dwell in their cell cytoplasm. Cell division involves separating of the genome which is in the form of tightly packed condensed structure known as the chromosomes, through movements directed by the cytoskeleton.

Figure 5: Eukaryotic cell