F plasmids

Definition

F plasmids are extrachromosomal DNA elements in bacteria that facilitate the transfer of genetic material through conjugation. They play a crucial role in horizontal gene transfer and antibiotic resistance.

5 Must Know Facts For Your Next Test

1. F plasmids contain genes necessary for the formation of a pilus, which connects donor and recipient cells during conjugation.
2. They can integrate into the host bacterial chromosome, forming an Hfr cell that transfers chromosomal genes more frequently.
3. F plasmids carry antibiotic resistance genes, making them significant in the spread of resistant bacterial strains.
4. During conjugation, a single strand of the F plasmid DNA is transferred from the donor to the recipient cell, where it is then replicated.
5. The presence of an F plasmid converts a bacterium into a donor (F+), capable of transferring genetic material to an F- (recipient) bacterium.

Review Questions

• What role do F plasmids play in bacterial conjugation?
• How do F plasmids contribute to antibiotic resistance?
• What happens when an F plasmid integrates into the host bacterial chromosome?

Related terms

Conjugation: A process by which one bacterium transfers genetic material to another through direct contact.

Hfr Cell: A bacterium with an integrated F plasmid that can transfer chromosomal genes during conjugation.

Antibiotic Resistance Genes: Genes that provide bacteria with resistance to antibiotics, often carried on plasmids like the F plasmid.