Final answer:
Escherichia coli (E. coli) can be made competent through artificial methods in a laboratory, allowing the bacteria to take up foreign DNA. Natural competence is rare in E. coli, and the process to make it competent involves treatment with calcium chloride and heat shock.
Step-by-step explanation:
The bacterium Escherichia coli (E. coli) can be made competent in a laboratory setting, although it is not naturally competent. Competent bacteria are those that can take up foreign DNA, and while some bacteria are naturally competent, E. coli typically requires artificial methods to increase cell membrane permeability and enable DNA uptake.
To render E. coli competent, one common method involves incubating the cells with an ice-cold solution of calcium chloride at 4°C, which helps the DNA molecules attach to the cell exterior. Subsequent incubation at 42°C facilitates the entry of DNA into the cell. Despite this process, transformation efficiency is relatively low; only about 0.01% of treated cells take up DNA successfully, so transformed cells must be selected from the non-transformed ones.
This process is essential for studies like genetic engineering or molecular biology research where horizontal gene transfer is induced. The ability to make E. coli competent is crucial for experiments involving gene expression, the study of mutated genes, or understanding bacterial virulence factors.