After the modified DNA is reinserted into the bacterial cell, why is then considered genetically modified or transgenic?
The correct answer and explanation is:
Once the modified DNA is reinserted into a bacterial cell, the cell is considered genetically modified or transgenic because it has undergone a change in its genetic material through human intervention. The process involves introducing foreign DNA into the organism’s genome, altering its original genetic code. This alteration can be achieved by inserting genes that confer new traits, such as resistance to antibiotics or the ability to produce a specific protein.
The term “genetically modified” refers to the fact that the genetic structure of the organism has been deliberately altered in a way that would not naturally occur through traditional reproduction. “Transgenic” is used specifically when the introduced genetic material is from a different species. For example, if a gene from a plant is inserted into a bacterium, the bacterium is transgenic because it now carries genes from a different organism.
In the context of genetic engineering, the process typically involves using tools like restriction enzymes to cut DNA and DNA ligase to join the foreign DNA into the target genome. The modified DNA can be introduced through methods such as electroporation, which uses an electric field to make the bacterial cell membrane more permeable, or by using a plasmid as a vector, which allows the gene to enter the bacterium.
Once inside the bacterial cell, the new genetic material is integrated into the bacterium’s genome, either at random locations or in a targeted manner. This modified cell now carries the new genetic instructions and will pass them on to its offspring. As a result, the bacteria will express the newly acquired traits, making the organism genetically modified or transgenic. This method of altering the genetic makeup of organisms has applications in medicine, agriculture, and research.