Biology

Difference between prokaryotic chromosomes and eukaryotic chromosomes

Main difference

The main difference between prokaryotic chromosomes and eukaryotic chromosomes is that prokaryotic chromosomes are present in the cytoplasm of the cell, they are short in size and contain circular DNA molecules, while eukaryotic chromosomes are present in the nucleus, they are in large long and have linear DNA structure …

Prokaryotic versus eukaryotic chromosomes

Prokaryotic chromosomes called chromosomes that are found in prokaryotic organisms and are found in circular double-stranded DNA structures. Eukaryotic chromosomes are the chromosomes found in eukaryotic organisms and have long strands of DNA, that is, a linear shape that contains genetic information. Prokaryotic chromosomes are present in the open cytoplasm of the prokaryotic organism, while eukaryotic chromosomes are present in the nucleus of the cell.

Prokaryotic chromosomes are haploid, that is, their genomes are uniquely present in the cell and do not have homologous chromosomes; however, eukaryotic chromosomes are diploid, that is, they appear in pairs with their homologous chromosomes in the cell. Prokaryotic chromosomes residing in the cytoplasm have direct contact with the cytoplasm and adhere to the cytoplasm from the inside, whereas eukaryotic chromosomes do not have contact with the cytoplasm, since they are located in the nucleus.

On prokaryotic chromosomes, genes are organized into operons, however, on eukaryotic chromosomes, these genes are regulated as singular structures. Prokaryotic chromosomes carried only a few proteins with their information during encoding. Eukaryotic chromosomes led to the encoding of larger proteins with the information contained in the genes. Prokaryotic chromosomes undergo genetic recombination through horizontal gene transfer, while eukaryotic chromosomes undergo genetic recombination through gamete fusion and meiosis.

Prokaryotic chromosomes associate with nucleoid-associated proteins that aid themselves in packaging, whereas eukaryotic chromosomes do not associate with nucleoid-associated proteins; rather, they form special structures known as nucleosomes by associating with histones. The structure of prokaryotic chromosomes also varies with respect to the presence of telomeres and centromeres, since they are short-sized, circular DNA chains; However, eukaryotic chromosomes have telomeres that are the end of each chromosome and centromere that acts as a point of attachment for two chromatids.

Prokaryotic chromosomes are only present alone without pairs and constitute the complete genetic information of the organism, but eukaryotic chromosomes are present in pairs and have several chromosomes that vary within each eukaryotic species. Prokaryotic chromosomes vary in their structure as they are short in size and have circular DNA strands, while eukaryotic chromosomes are long in size and have linear DNA strands. Prokaryotic chromosomes replicate at the beginning of cell division to form sister chromatids, while eukaryotic chromosomes replicate when they enter the S phase of the cell cycle.

Comparative chart

Prokaryotic chromosomes Eukaryotic chromosomes
Prokaryotic chromosomes are found in prokaryotic organisms, which have double-stranded circular DNA structures. Eukaryotic chromosomes are the chromosomes found in eukaryotic organisms, which have long chains of DNA structures.
Quantity
Single Several chromosomes in a cell.
Idea
In cytoplasm In core
Homologous chromosomes
Not present Present
Contact with the cytoplasm
Directly in contact with the cytoplasm no contact
Structure
Short and circular Long and linear
Telomeres and Centromeres
Absent Present
Association with proteins
Associated with nucleoid-associated proteins Forming nucleosomes by associating with histones
DNA replication
At first During the S phase of the cell cycle
Origin of replication
Single origin Multiple origins
Genetic structure
Organized in operons Individual structures
Number of Proteins
Code in a few proteins Code to a higher amount of proteins
Genetic recombination
Through horizontal gene transfer Via meiosis and gamete fusion

What are prokaryotic chromosomes

Prokaryotic chromosomes are the chromosomes found in prokaryotic organisms and found in circular double-stranded DNA structures. These are present in the open cytoplasm of the prokaryotic cell and have direct contact with the cytoplasm and are attached to the cytoplasm from the inside. These chromosomes are haploid, that is, their genomes are uniquely present in the cell and do not have homologous chromosomes. That is the reason why these chromosomes are found alone without pairs and constitute all the genetic information of the organism.

Prokaryotic chromosomes also vary in their structure, as they are short in size and have circular DNA strands. They do not have telomeres or centromeres, as they are short in size and are circular DNA strands. The genes on these chromosomes are organized into operons and can encode only a few proteins with the information that resides in their structures. They also associate with nucleoid-associated proteins that help themselves to pack their structure.

Prokaryotic chromosomes undergo genetic recombination through horizontal gene transfer and undergo a replication process at the beginning of cell division to form sister chromatids.

What are eukaryotic chromosomes

Eukaryotic chromosomes are the chromosomes found in eukaryotic organisms that comprise longer strands of DNA. These chromosomes are found in linear structures in the cell of these organisms. Unlike prokaryotic chromosomes, these are present in the nucleus of the cell and do not have contact with the cytoplasm of the cell. These are singular and linear structures and contain the information for the coding of proteins, that is to say, genetic information for organisms. These chromosomes lead to the encoding of larger proteins.

Eukaryotic chromosomes have telomeres and centromeres. These telomeres are the end point of each chromosome, and the centromeres are the place on the chromosome denser than the rest of the chromosome, which acts as a junction point for two chromatids. These chromosomes are in pairs and have several chromosomes that vary within each eukaryotic species. That is why it is known to be diploid.

Eukaryotic chromosomes do not associate with nucleoid-associated proteins; rather, they form special structures known as nucleosomes by associating with histones. They undergo genetic recombination through gamete fusion and meiosis and replicate when they enter the S phase of the cell cycle, unlike prokaryotic chromosomes that experience during the onset of the cell cycle.

Key differences
  1. Prokaryotic chromosomes are found in prokaryotic organisms and are in double-stranded DNA structures, while eukaryotic chromosomes are found in eukaryotic organisms and have long DNA strands.
  2. Prokaryotic chromosomes are uniquely presented; on the other hand, eukaryotic chromosomes are present in greater numbers.
  3. Prokaryotic chromosomes are present in the open cytoplasm; on the contrary, eukaryotic chromosomes are present within the nucleus of the cell.
  4. Prokaryotic chromosomes are haploid and do not have homologous chromosomes; however, eukaryotic chromosomes are diploid as they appear in pairs.
  5. Prokaryotic chromosomes have direct contact with the cytoplasm; on the other hand, eukaryotic chromosomes have no contact with the cytoplasm.
  6. Prokaryotic chromosomes are short in size and have circular DNA strands, but eukaryotic chromosomes are long and have linear DNA strands.
  7. Prokaryotic chromosomes do not have structures such as telomeres and centromeres; in contrast, eukaryotic chromosomes have telomeres and centromeres.
  8. Prokaryotic chromosomes associate with nucleoid-associated proteins; on the other hand, eukaryotic chromosomes do not associate with nucleoid-associated proteins; rather, they form nucleosomes by associating with histones.
  9. Prokaryotic chromosomes replicate at the beginning of cell division, but eukaryotic chromosomes replicate when they enter the S phase of the cell cycle.
  10. Genes on prokaryotic chromosomes are organized into operons, whereas on eukaryotic chromosomes, these genes are regulated as singular structures.
  11. Prokaryotic chromosomes encode only a few proteins, on the other hand, eukaryotic chromosomes encode larger proteins.
  12. Prokaryotic chromosomes undergo genetic recombination through horizontal gene transfer, while eukaryotic chromosomes undergo genetic recombination through gamete fusion and meiosis.

Final Thought

Prokaryotic chromosomes are present in the cytoplasm of the cell, they are short and circular DNA structures, and have the unique origin of replication per chromosome, while eukaryotic chromosomes are present in the nucleus of the cell, long, with DNA structure linear and have multiple origins of replication.

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