Do Prokaryotes Have Telomeres: Why, How And Detailed Insights

A telomere is a region or a portion on the chromosome that is present at the end, that is the final region of the chromosome is the telomere part. So, do prokaryotes have telomeres in them?

Do prokaryotes have telomeres, No. Prokaryotic organisms are very basic organisms that do not have telomeres in their chromosomes. Telomeres are present only in the chromosomes of eukaryotic organisms.

But why do prokaryotic organisms not have telomeres in their chromosomes and what is their ultimate function in eukaryotes? Let’s see all the answers in this article.

What are telomeres?

Telomeres are the region in the chromosome.

Telomeres are the portion in the chromosome that does not carry any genetic information and present at the end. 

They are present only in eukaryotic organisms. Prokaryotic organisms lack telomeres in their chromosomes.

do prokaryotes have telomeres
Image credits- Pixabay

Why do prokaryotes not have telomeres?

We just saw that the telomeres are present at the end of chromosomes. In order to identify the end or start of the chromosome, the chromosome should be in a straight or linear form.

Prokaryotes have a single circular-shaped chromosome. Their replication process is much faster than eukaryotic organisms. As they are circular in shape, there is no end and telomeres are absent in prokaryotes.

Do prokaryotes have telomeres like any other structures?

No, in prokaryotes there is no structure like telomeres.

Why do eukaryotes have telomeres?

We just saw that prokaryotes have a round or circle shaped chromosome so there is no end for prokaryotic chromosomes to be identified.

In the case of eukaryotes, They have a linear or straight chromosome in which the end or the final part is identifiable. This is why telomeres are present only in eukaryotes. 

Telomeres play a significant role in protecting the chromosome from any damage, cell division process, cell aging process, DNA replication and transcription process.

What are the functions of telomeres in eukaryotic organisms?

  • The stability of chromosomes is due to the telomeres as they are present at the end.
  • There will be the destruction of chromosomes during the process of DNA replication. The non-coding sequences at the last of the chromosomes (Telomeres) are lost in this process.
  • Telomeres are present for the protection of genetic information.

Characteristics of nucleoid:

  • The shape of the Nucleoid is an irregularly shaped part in the cytoplasmic region of the prokaryotic cell that contains the genetic material or so-called genophore.
  • It is different from the nucleus as the nucleus has a membrane outside it. Nucleoids do not have membranes in them.
  • About 60% of the nucleoid is DNA (Genetic material that has the genetic information in it.
  • The other 40 % are other RNAs or proteins.
  • The main function of the nucleoid is to control the activity of the cell and its reproduction and maintain the genophore intact.

So how are the prokaryotic chromosome structure? Let’s see in detail.

Prokaryotic Chromosome structure:

  • Prokaryotes do not have a true or membrane bound nucleus in them. The chromosomes in prokaryotes are present in the region of cytoplasm where the genetic material embedded which is called nucleoid of the cell.
  • The chromosomes in prokaryotic cells are round or circular in shape. Mostly they are single. Few exceptions are present. They are highly coiled structures with double strands.
  • Only a single chromosome is present but the single chromosome has a large strand of DNA molecule that is highly coiled and placed inside it.
  • Prokaryotic DNA is wrapped with NAPs that are Nucleoid associated proteins which aids in the process of DNA replication and transcription.
  • Prokaryotes are haploid in nature. There are no pairs of chromosomes in prokaryotes.
  • Prokaryotes have a small portion or a molecule of DNA called plasmids which plays a vital role in genetic engineering.
  • So prokaryotes have chromosomal DNA and Plasmid DNA.

Read more on DNA Supercoiling

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