Final answer:
Bacterial cells must be in a physiological state called competence to take up free exogenous DNA from the environment. Competence refers to the ability of bacteria to actively bind to environmental DNA, transport it across their cell envelopes, and recombine it into their genome. Some bacteria are naturally competent, while others need to be made artificially competent through physical or chemical treatments.
Step-by-step explanation:
In order for a bacterial cell to take up free exogenous DNA from the surrounding environment, it needs to be in a physiological state called competence. Competence refers to the ability of bacteria to actively bind to environmental DNA, transport it across their cell envelopes, and make it single stranded for recombination into their genome. Some bacteria, like Bacillus spp., are naturally competent, while others need to be artificially made competent through physical or chemical treatments. Examples of physical methods include heat shock and electroporation, while chemical methods involve neutralizing charges on the cell membrane.