Prokaryotic Genetics and Chromosomes

Prokaryotic Genetics

• Prokaryotic cells have a single circular chromosome, unlike eukaryotes which have multiple linear chromosomes.
• Humans have 23 pairs of chromosomes.
• Prokaryotic cells also contain extrachromosomal genetic material in the form of plasmids.
• Plasmids are double-stranded circular DNA molecules.
• Plasmids contain genes for antibiotic resistance.
• Plasmids can be transferred between bacterial cells.
• Plasmids are used in genetic engineering as gene transfer vectors.
• Plasmids are naked (not associated with proteins).
• Plasmids have a few thousand nucleotides base pairs (bp).

Prokaryotic and Eukaryotic Chromosomes

• Prokaryotic cells have a single circular chromosome located in the cytoplasm, while eukaryotic cells have multiple linear chromosomes in a nucleus.
• The prokaryotic chromosome lacks histones to compact the DNA.
• Eukaryotic chromosomes are associated with histones for packaging.
• Both types of cells' DNA contains genetic codes for proteins.

Bacterial vs. Viral Genome

• Bacteria have a single circular chromosome containing genetic information.
• Viruses can have either DNA or RNA as their genetic material.
• The protein coat surrounding the viral nucleic acid is called a capsid.

Plasmids

• Plasmids are circular DNA molecules found in some prokaryotic cells.
• They contain a few thousand nucleotide base pairs.
• Plasmids are naked (not associated with proteins).
• Plasmids enable the transfer of antibiotic-resistance genes between bacterial cells.
• Plasmids are used in genetic engineering as vectors to transfer genes.

Specialized Plasmid Vectors

• Specialized plasmids are used for cloning DNA.
• Restriction nucleases cut DNA.
• DNA ligase joins DNA fragments.
• This process creates recombinant DNA, introducing a new gene into a plasmid.
• Recombinant plasmids are then incorporated into bacterial cells, allowing for gene cloning.

Practical DNA Technology Uses- Retrovirus Vector in Gene Therapy

• Gene therapy involves introducing genetic material into cells to treat a disease.
• Retroviruses are vectors that serve to transfer normal genes into patient cells.
• Steps involve isolating a normal gene, cloning it, incorporating it into a retrovirus, and infecting bone marrow cells with the modified retrovirus.
• The genetically modified cells are then reintroduced into the patient.
• The outcome is observed for successful expression of the normal gene.

Explore the fascinating world of prokaryotic genetics, focusing on the structure of prokaryotic chromosomes and the role of plasmids. This quiz covers key differences between prokaryotic and eukaryotic cells, including how genetic material is organized and utilized in various biological processes.