Read this excerpt from a passage.
"A genetically modified organism is one whose genes have been altered. Genes from one species are inserted into a second species. The goal of this process is to introduce a desired trait or characteristic into the second species. For example, corn is vulnerable to certain kinds of worms that eat and destroy the corn stalks. Genes can be taken from some bacteria and inserted into the corn. These genes from the bacteria enable the corn to produce proteins that kill the worms. This genetically modified corn is now resistant to these pests. Other plants, such as tomatoes, have been genetically altered in a similar fashion, to remain fresher longer."
Which type of definition does this excerpt provide?
extended definition
formal definition
narrative definition
explanatory definition