Creating a transgenic organism involves the introduction of genes to the organism’s original genome by way of biological vectors. The products attained from this type genetic engineering are referred to as genetically modified organisms (GMOs) and express transgenes derived from either the same or a different species of organism. There are three major steps in creating a genetically modified organism: identifying and isolating the desired transgene, inserting the transgene into the host's genome, and growing the engineered crop. When using biological methods to genetically modify an organism, two vectors are used when inserting the transgene into the main genome: the vector containing transgene DNA and the Ti plasmid of Agrobacterium tumefaciens. Containing genes necessary for genetic incorporation to occur in the host plant, the latter is a vital inclusion to the process of creating GMOs (1). In order for a transgene to function in its new host, promoter and terminator sequences must be included, creating a gene cassette which regulates the expressed region of the transgene (2). CaMV35S is the most commonly-used promoter in modified plants; with the Ti plasmid comes the NOS terminator, the most common terminator (2).

(1) McBride, K. E., and K. R. Summerfelt. Improved Binary Vectors for Agrobacterium-Mediated Plant Transformation. 14 Feb. 1990. National Library of Medicine: National Center for Biotechnology Information, doi:10.1007/BF00018567. Accessed 16 Apr. 2021.

(2) MiniPCR GMO Learning Lab: Heart-Shaped Bananas. Amplyus, 2018.