Transduction in bacteria is mediated by

Explanation

Let's explain each option individually: a) Plasmid vectors: Plasmid vectors are small, circular DNA molecules that can be used to carry foreign DNA and introduce it into bacterial cells during genetic engineering experiments. However, plasmids are not involved in transduction in bacteria. b) Phage vectors: This option is correct. Transduction in bacteria is mediated by phage vectors. Bacterial transduction is a process in which bacteriophages (viruses that infect bacteria) transfer bacterial DNA from one bacterium to another. During the lytic cycle of bacteriophage infection, the phage can accidentally package a fragment of bacterial DNA from the host cell into its viral capsid. When this bacteriophage subsequently infects another bacterium, it can inject the bacterial DNA fragment into the new host cell. This results in the transfer of bacterial genes from one bacterium to another, effectively mediating horizontal gene transfer in bacteria. c) Cosmids: Cosmids are hybrid plasmids that combine the features of plasmids and bacteriophage lambda vectors. They are used in molecular biology for cloning large fragments of DNA. While cosmids can be used for cloning, they are not directly involved in transduction in bacteria. d) F-factors: F-factors, also known as fertility factors or sex factors, are plasmids found in certain bacteria, such as Escherichia coli (E. coli). They play a role in bacterial conjugation, a form of direct DNA transfer between bacterial cells. F-factors are not directly involved in transduction, which is a process mediated by bacteriophages (phages). In summary, the correct answer is b) Phage vectors. Transduction in bacteria is mediated by bacteriophages (phages) that transfer bacterial DNA from one bacterium to another during the process of viral infection. This horizontal gene transfer mechanism can lead to the exchange of genetic material and contribute to the genetic diversity of bacterial populations.