Plasmid - GCSE Biology Definition

A plasmid is a small, circular piece of DNA found in bacterial cells and sometimes in other organisms. Unlike the main bacterial chromosome, plasmids are separate and can carry extra genes that provide advantageous genes, such as antibiotic resistance. In genetic engineering, scientists use plasmids because they can be transferred between cells and used to insert new genes into organisms. Plasmids are important in biotechnology and are a key concept in GCSE Biology.