The prokaryotes are the one that consist of the domains of age Archaea and the Eubacteria. Some examples of them are cyanobacteria, the bacteria and archaea.
With concern to the question for is prokaryotic DNA circular or linear, most of the cells of the prokaryotes have chromosome which is singular and is actually circular. Thus, they have circular DNA.
The cells of the eukaryotes have the chromosomes which are linear in shape and have terminal ends. In most of these, the DNA is seen to be arranged in many linear chromosomes. Also, the linear is just not always concerned with the eukaryotes. Eukaryotes have their DNA in the nucleus having a nuclear membrane.
Some of the organism which are termed to be prokaryotic also have linear chromosomes leading them to also have DNA being linear in shape. One such example of it is Borrelia Burgirferi. There are experiments that show that some of the prokaryotes can contain to maintain viability with linear ones.
There are quite a lot factors that determine the linear DNA getting evolved with one of the best suited explanation to be the selective pressure which is in favor of the ones that related the length of genome of an organism. There can be clarity for mutation with concern with the type of DNA.
The prokaryotic ones that have linear DNA can face up problem like the one with the end replication issue. This is the time when the issue is raised by the directionality of the DNA enzymes getting replicated which ends up in much loss of the genetic substances in the end of the linear cycle of cell and replication.
Borrelia burgdorferi
They are the species of bacteria and of the class spirochete in the genus of Borrelia which caused the Lyme disease.
The concerned query for is the prokaryotic DNA circular or linear, the answer quite contradicts to the actual. The prokaryotes have circular DNA but however this species of bacteria have linear chromosome.
They were termed to be the third genome of microbe that was sequenced after the Mycoplasma in 1995. It has linear chromosome which has 853 genes and 910,725 base pairs. The method that was used up to get it sequenced was the whole genome shotgun.
There are quite a lot variation in genomes of it which plays to contribute in various dissemination and disease. The specific group of genome has much variety of genomes on the membrane receptors that are specific to the host infection.
Why is prokaryotic DNA circular?
The cells of the prokaryotes do have chromosome which is single and is circular in shape and is seen in nucleoid.
The molecules in the circular DNA is made to get extracted from the bacteria that are mesospheric and have a lacking of duplex that turns out to be relative compared to the linear DNA of the equal size. This lacking of the duplex causes an exertion of strain on the DNA and then making it to coil up.
There are many of the organism that are prokaryotes have a typical cell with also linear chromosome but is mostly circular which is cause they trend to replicate faster than the cells of the eukaryotes making DNA replications take place during division of cell.
Mostly the prokaryotic cell carry a little amount of the genetic substance in the form of the chromosome or molecules in single quantity of the DNA that is circular. The prokaryotic DNA is placed in the center of the cell and is called the nucleoid and does not have any nuclear membrane.
The DNA has in general a charge which is negative inside the cells of bacteria and do lack the helical turns. The DNA is not nor overwound or under overwound but takes up the confirmation of being relaxed.
How is DNA organized in prokaryotic cells?
The cells of prokaryotes lack a nucleus and have no nuclear membrane as well which leaves it to having a nucleoid.
The genetic substances in the cells of the prokaryotes are carried by a single piece of DNA that is circular and is linked to the membrane of cell and comes in direct touch with the cytoplasm.
The prokaryotic DNA is circular and a double helix structure and is a single chromosome. The structure of double helix is enclosed around the proteins to make the nucleosomes. The DNA is packed up quote tight to let in fit inside.
The gene of the prokaryotic microbes is organized all together in a form of cluster and is called the lac operon. The organization form of the DNA in the prokaryotes thus is different from that of the eukaryotes in many separate ways. The most obvious difference is the process of condensation that the prokaryotic molecules of DNA undergo to for in the cells.
Inside the eukaryotes the material of genes is a home to the nucleus and is kept packed as the linear chromosome. The chromosome is made up of the complex of DNA protein and is called chromatin which islet to kept organized into the subunits called the nucleosomes.
Do prokaryotes have non coding DNA?
The genomes of the prokaryotes seem to be much compact and gets transcript often and covers one or more genes.
It was in original advice that over the 98% of the human genomes have not been encoded with the sequences of protein that consists of most of the one in the introns while 20% of the prokaryotic genome stays non-coded.
In almost all the eukaryotes, the large mass of the genome stays up for the non-coded in form of proteins. The part of the eukaryotic genomes that is non-coded is likely to have been expanded through the various mechanisms via evolution like that of the deletion and insertion of the DNA.
The non-coding sequence of the DNA is the one that do not tend to get coded for the amino acids. Most of the non-coded DNA lies in between the genes of the chromosome and has been found to give zero function. There is other DNA which is non-coded and is called the introns and is found inside the genes.
The eukaryotic organism seem to be much complex than the prokaryotic ones which leads to the cells of the eukaryotes to have more number of DNA than the other. The cells of the eukaryotic organism tend to be more complex and are made of the DNA and the protein histones.
DNA in extant prokaryotic cell is circular?
There is formation of two copies as the outcome after replication with one getting separated from another cause of the cell growth.
There is evidence to proof that the DNA of the prokaryotes are circular and are single chromosome. The cells of the prokaryotes do not tend to go for mitosis and thus the chromosome is seemed to replicate and result in two copies.
The prokaryotes do not have any nucleus and thus yet the DNA of them are not scattered all over the cell. The DNA is kept inside the nucleoids of the prokaryotes and is circular with being double stranded and is coiled up tight. As for the structure being a circle and coiled tight, the DNA is not scattered in the cell.
In many of the organism like that of the humans, the chromosomes are linear but in the organism like in that of bacteria or the archaea they are typical being circular. The DNA of the prokaryotes is concerned in the nucleoid which is in the center of the cell.
Also Read:
- Dna transcription types
- Do protists have a cell wall
- Do bacteria form endospores
- Is adenine a pyrimidine
- Do all cells have cytoplasm
- Do eukaryotes have endoplasmic reticulum
- Globular protein functions
- Do stem cells have a nucleus
- Multiple alleles example 2
- Hypertonic vs hypotonic
I am Ankita Chattopadhyay from Kharagpur. I have completed my B. Tech in Biotechnology from Amity University Kolkata. I am a Subject Matter Expert in Biotechnology. I have been keen in writing articles and also interested in Literature with having my writing published in a Biotech website and a book respectively. Along with these, I am also a Hodophile, a Cinephile and a foodie.