Which of the following statements about plasmids is true?

Plasmids are small, circular DNA molecules that exist independently of chromosomal DNA within bacterial cells. One of their key features is their ability to carry genes that can provide various benefits to bacteria, with antibiotic resistance genes being among the most significant. The presence of these genes allows bacteria to survive in environments that are challenging due to the presence of antibiotics, providing a selective advantage in such situations.

The significance of plasmids in the context of antibiotic resistance stems from their capacity to be transferred between bacteria through processes such as conjugation. This horizontal gene transfer contributes to the rapid dissemination of resistance traits within bacterial populations, making them an important concern in the field of microbiology and antimicrobial treatment.

In contrast, other statements about plasmids do not accurately reflect their biological characteristics. For example, plasmids are indeed common in bacteria, they have the ability to replicate independently of the bacterial chromosome, and they are not always harmful; in fact, they can be beneficial for bacterial adaptation and survival. Understanding the role of plasmids in antibiotic resistance is critical in combating infections and managing antibiotic therapy effectively.