Prokaryotes

Prokaryotes are unicellular organisms with no membrane barrier, such as a nucleus or other organelles of organized compartments. Usually, prokaryotes are less in size than eukaryotic cells; their size may vary between 0. 1 and 5. 0 micrometers in diameter. Besides, their DNA is mapped in a structure called a nucleoid, which may be a single circular chromosome. In addition, they possess organelles called plasmids, which are also small circular DNA molecules containing other genes.

Prokaryotes only reproduce asexually, and one method of reproduction we have seen is binary fission. This type of cell division results in two daughter cells. They seem to acquire different metabolic processes, meaning that the organisms prefer different environments, including soil and hot springs. Some of the prokaryotes are capable of moving with the use of appendages such as flagella or cilia.

Prokaryotes are divided into two main domains: bacteria and archaea. Bacteria belong to the microscopic organisms, and like any other organisms, there are thousands of each recognized species, and they are present in almost every environment on the planet. It exists in several forms, which are cocci ( spherical shaped), rod-shaped bacilli, and spirillas that are spiral-shaped. Bacteria, however, are biochemically and genetically different from archaea and are usually found in harsh conditions like salt flats and geysers. Cell membranes in their structure possess peculiar lipids that do not belong to any of the forms mentioned earlier.

Prokaryotes have several important functions of nutrient cycling, for example, nitrogen fixation as well as decomposition, which assists in the organic matter cycle. Some of the bacteria can be destructive, forming diseases, while others are useful and needed in the body, such as those existing in the digestive system. They are very important in biotechnology, where they are used in synthesizing antibiotics, enzymes, and biofuels.

Does prokaryotes have chromosomes?

Yes,

In fact, both bacteria and archaea that are classified under the prokaryotes possess a chromosomes. Prokaryotic chromosomes will be circular and not protected by nucleic as with many eukaroytes. They commonly contain a single circular chromosome, but they may possess other strands of DNA called the plasmids.

Prokaryotic cell chromosome

Structure

Shape: Whereas the prokaryotic chromosome is circular, the eukaryotic chromosome is of linear type.

Location: They are located in a section of the cell called the nucleoid, and unlike other body parts, they are not contained in a skin known as a membrane. This is in contrast with eukaryotic cells, where the chromosomes are found within a well-defined nucleus.

Composition

DNA: The prokaryotic chromosome has a single-stranded circular DNA molecule. They may also contain plasmids, which are small circular DNA molecules that carry additional genes

Proteins: In prokaryotes also the DNA is complex with proteins but these proteins are of different type from the kind of histone proteins seen in eukaryotes. It helps in the packaging of the DNA as well as controlling its processes.

Replication

Binary Fission: Concerning the reproduction of the DNA in prokaryotes, the most common mode is binary fission. and for such a circular chromosome to be replicated, the cell divides and ensures a copy of such a daughter cell is passed.

Plasmids

Additional DNA: Besides this main featured chromosome, most of the prokaryote cells possess other round, compact bodies of DNA known as plasmids that are capable of replicating on their own. With these genes on the plasmids are other genes that will be helpful to the bacteria, such as genes that will make it resistant to antibiotics.

Genetic Exchange

Horizontal Gene Transfer: This means that prokaryotes do not have to reproduce sexually; however, there are many ways through which they can exchange genetic products, and some of them include transformation, transduction, as well as conjugation.

Examples

Bacteria: Most bacteria have a single circular chromosome, with some exceptions where the organism can possess more than one chromosome.

Archaea: Another point is that Archaea involves circular chromosomes, and in this case, they resemble the eukaryotic DNA more as it refers to the packing and the replication.