What is Plasmid DNA?
Essential genetic information is passed on to the next individual as part of the inheritance process during reproduction. Plasmid DNA is extrachromosomal DNA that is different from genomic DNA. It is circular in form and usually occurs inside bacterial cells. When compared to chromosomes, it is a smaller molecule with a variable number of copies in each cell. It has a replication origin, hence it is self-replicative by definition.
As a result, they are not reliant on genomic DNA and are capable of self-replication. This DNA codes for genes that produce results that aren't required for cell activity, such as nitrogen fixation, antibiotic resistance, and so on. As a result, genetic engineering can be used to introduce new genes.
A plasmid DNA is a small circular piece of DNA that can independently replicate without the host’s chromosomal DNA.
It is found in bacteria and exists naturally in eukaryotes like plants and yeast and can also be found in archaea.
Some of the functional benefits of plasmid DNA to its host include degradative functions, resistance to antibiotics, and virulence.
Natural plasmid DNA has an origin of replication and a gene such as an antibiotic resistance gene. On the other hand, artificial plasmid DNA used in laboratories is designed to introduce foreign DNA into another cell. The latter kind of plasmid DNA consists of an origin of replication, cloning site, and selection marker.
Scientists or bioengineers find plasmid DNA as a great tool as it is easily modifiable and has the ability to self-replicate within a cell making it easier to study and experiment.
What is Chromosomal DNA?
The genomic DNA found in prokaryotic and eukaryotic species is referred to as chromosomal DNA. Prokaryotic genomes have a single circular chromosome, whereas eukaryotic genomes have linear chromosomes. They are double-stranded and contain a replication origin; the occurrence of several replication origins in eukaryotes is due to their huge size. The number of chromosomes in a particular type varies from species to species.
Chromosomal DNA is a DNA molecule having all of the genetic information in the genome of an organism.
Most of the eukaryotic chromosomal DNA consists of packaging proteins and chaperone proteins which bind to the DNA molecule and condense it to prevent tangling and becoming an unorganised structure.
An important function of chromosomal DNA is to carry genetic information which is the functional unit of heredity. As we know, a gene is a segment of DNA that consists of instructions to make a particular protein or related proteins, and this gene is carried by the chromosomes. Chromosomes contain many genes and are present within the cell nucleus and mitochondria.
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Chromosomal DNA vs Plasmid DNA
In the above tabular chart, we discussed the difference between plasmid and chromosomal DNA, now we shall see the existing similarities between the two.
Similarities Between Plasmid and Chromosomal DNA
Both plasmid DNA and chromosomal DNA are present in bacterial cells.
Both chromosomal DNA and plasmid DNA contain genes and are composed of DeoxyriboNucleic Acid (DNA).
Both are highly significant on their own terms.
FAQs on Difference Between Plasmid DNA and Chromosomal DNA
1. Distinguish between plasmid DNA and chromosomal DNA.
Plasmid DNA and chromosomal DNA, both, contain genetic material, however many differences exist between the two. The former kind is present only in bacterial cells whereas the other is present in bacterial cells as well as eukaryotic cells. Plasmid DNA is called extrachromosomal DNA and its genetic material is not too vital for hereditary purposes, whereas the latter has great importance in carrying genetic information from one generation to another. Plasmid DNA is used as vectors in biotechnological studies and has importance in molecular biology. It also provides resistance from pesticides, insecticides, and herbicides to bacterial cells. Plasmid DNA is self-replicative whereas chromosomal DNA uses the genome for replication.
2. What are the shapes of plasmid DNA and chromosomal DNA?
Plasmid DNA is linear in shape whereas chromosomal DNA can be linear or circular in shape. Naturally, plasmid DNA is present as a tightly supercoiled circle to allow itself to fit inside the cell. Chromosomal DNA is often observed as X-shaped structures.
3. Is plasmid DNA transferable across bacteria?
The process of conjugation allows several plasmids to transfer themselves across bacterial cells. Transferability is a property of F-type and P-type plasmids, which means they may travel from one bacterial cell to another. The recipient cell has now transformed into a donor cell and is ready to begin conjugation with another recipient.
4. What is the purpose of using plasmid as a vector?
Plasmids are non-chromosomal, self-replicating, double-stranded, closed, and circular DNA molecules found in bacteria. Plasmids have enough genetic information to replicate themselves. Plasmids are utilised as vectors because when introduced into them, they can carry a foreign DNA fragment.
