--- title: "Horizontal Gene Transfer: Uptake, Contact and Delivery" description: "Bacteria can acquire DNA by taking up naked DNA, receiving bacterial DNA in a phage particle, or transferring DNA through direct cell contact. Transfer can occur between species, so a transferred gene" canonical: https://lightmysky.com/learn/science/horizontal-gene-transfer-uptake-contact-and-delivery-mt_mrmn0_nQf7 source: https://lightmysky.com/learn/science/horizontal-gene-transfer-uptake-contact-and-delivery-mt_mrmn0_nQf7.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Horizontal Gene Transfer: Uptake, Contact and Delivery Bacteria can acquire DNA by taking up naked DNA, receiving bacterial DNA in a phage particle, or transferring DNA through direct cell contact. Transfer can occur between species, so a transferred gene's ancestry may differ from the ancestry of its host cells. Subject: Science · Area: Microbiology · Ages 20 to 21 Page: https://lightmysky.com/learn/science/horizontal-gene-transfer-uptake-contact-and-delivery-mt_mrmn0_nQf7 ## Ready when they can - Distinguishes the three routes by what carries the DNA and what the recipient must do. - Interprets controlled membrane and DNase experiments to identify which transfer routes the results exclude. - Explains why transfer complicates a phylogeny built from a single gene. ## Lesson: Three ways to borrow genes Horizontal transfer moves DNA between cells rather than only from parent to offspring. Transformation imports naked DNA from the surroundings into a competent cell, one able to take it up. Transduction uses a bacteriophage, a virus of bacteria, to deliver bacterial DNA. Conjugation transfers DNA from a living donor by direct contact with a recipient. A pilus helps establish contact in many systems. *(drawing: Stages of conjugation, not cell structures. The transferred DNA may be plasmid DNA or chromosomal DNA.)* To test routes, remove one requirement and check the controls. A membrane excludes conjugation only if cells cannot cross or contact each other. Check that free DNA and the relevant phage can pass before interpreting the other routes. DNase destroys exposed DNA. To test transformation, apply it before uptake and verify DNA removal, cell survival and continued function of the other routes. Continued transfer then excludes transformation, not both other routes. A phylogeny is a tree of inferred ancestry. Vertical inheritance passes DNA from parent to offspring. A horizontally transferred gene may have a different history from its host cells, so one gene tree can misrepresent cell ancestry. Compare several independent genes with evidence of mainly vertical inheritance. Tree disagreement can suggest transfer, but errors in inference can also cause it. DNA entry does not guarantee inheritance by descendants. Incoming DNA must be maintained, for example by joining the chromosome or replicating as a plasmid. DNA that is degraded without leaving a retained copy cannot be passed on. Distinguish evidence that DNA entered a recipient from evidence that the recipient's descendants inherited it. **Recap.** Trace the DNA carrier, check the experimental controls, and distinguish gene history from host-cell ancestry. *Lesson explanations, questions and study cards were written for this dataset, with scientific background from Microbiology.* ## Practice 8 questions on this page, each with its working shown. ## Optional connections - [Bacteriophages as Predators and as Laboratory Tools](https://lightmysky.com/learn/science/bacteriophages-as-predators-and-as-laboratory-tools-mt_vOnjSpXjrj) ## Opens up - [Plasmids, Mobile Elements and How Resistance Spreads](https://lightmysky.com/learn/science/plasmids-mobile-elements-and-how-resistance-spreads-mt_Vk0qOY64qv)