An Interactive Introduction to Organismal and Molecular Biology, 2021

22.
GENETIC ENGINEERING
Andrea Bierema
Learning Objectives
Students will be able to
• Describe examples and mechanisms of genetic engineering.
• Define genetically modified organisms (i.e., GMO).
• Explain how CRISPR is used.
• Describe the role of Cas9 and the guide RNA in CRISPR.
• Identify key steps and their variations in CRISPR.
A variety of biotechnologies exist including cloning organisms, sequencing DNA, and modifying DNA.
Although there is a wide range of molecular biotechnologies, this chapter focuses on changes to the genome,
which results in changes in proteins or protein synthesis: genetic engineering.
Introduction to Genetic Engineering
Genetic engineering refers to the direct manipulation of DNA to alter an organism’s characteristics (phenotype)
in a particular way. This may mean changing one base pair (A-T or C-G), deleting a whole region of DNA,
or introducing an additional copy of a gene. It may also mean extracting DNA from another organism’s
genome and combining it with the DNA of that individual. It has been used by scientists to enhance or modify
the characteristics of an individual organism from a virus to sheep, to possibly humans. For example, genetic
engineering can be used to produce plants that have a higher nutritional value or can tolerate exposure to
herbicides.