质粒是封闭的、圆形的DNA片段，能够自我复制，并由许多细菌携带。它们为细菌提供了独特的功能，使它们能够进行有性复制并在彼此之间传递遗传物质。质粒还负责赋予抗生素抗性的遗传因子，并提供分解代谢不良的食物资源所需的酶。作者对质粒的结构、功能和应用进行了更新的论述，适合本科生和医学生学习。采用独创的教学视角--将质粒作为具有共生或寄生生存模式的生物体进行研究，本文为理解质粒在进化背景下的结构和功能提供了一个重要的框架.最新的质粒教科书创新的教学视角使学生易于理解包含质粒对临床和生物研究的重要性的关键章节。

Plasmids are closed, circular pieces of DNA that are able to self-replicate and are carried by many bacteria. They provide unique functions for bacteria by allowing them to sexually replicate and to pass on genetic material between each other. Plasmids are also responsible for the genetic factors that give resistance to antibiotics, and provide the enzymes needed to break down poorly metabolised food resources. The author has provided an updated treatment of the structure, function and application of plasmids suitable for undergraduates and medical students. Employing an original teaching perspective--examining plasmids as living organisms with either a symbiotic or parasitic mode of survival--this text provides an important framework for understanding the structure and function of plasmids in an evolutionary context.The most up to date text on plasmidsAn innovative teaching perspective makes for easy student understandingContains crucial chapters on the importance of plasmids for clinical and biological research