Connection for AP® Courses
Did you eat cereal for breakfast or tomatoes in your dinner salad? Do you know someone who has received gene therapy to treat a disease such as cancer? Should your school, health insurance provider, or employer have access to your genetic profile? Understanding how DNA works has allowed scientists to recombine DNA molecules, clone organisms, and produce mice that glow in the dark. We likely have eaten genetically modified foods and are familiar with how DNA analysis is used to solve crimes. Manipulation of DNA by humans has resulted in bacteria that can protect plants from insect pests and restore ecosystems. Biotechnologies also have been used to produce insulin, hormones, antibiotics, and medicine that dissolve blood clots. Comparative genomics yields new insights into relationships among species, and DNA sequences reveal our personal genetic make-up. However, manipulation of DNA comes with social and ethical responsibilities, raising questions about its appropriate uses.
Nucleic acids can be isolated from cells for analysis by lysing cell membranes and enzymatically destroying all other macromolecules. Fragmented or whole chromosomes can be separated on the basis of size (base pair length) by gel electrophoresis. Short sequences of DNA or RNA can be amplified using the polymerase chain reaction (PCR). Recombinant DNA technology can combine DNA from different sources using bacterial plasmids or viruses as vectors to carry foreign genes into host cells, resulting in genetically modified organisms (GMOs). Transgenic bacteria, agricultural plants such as corn and rice, and farm animals produce protein products such as hormones and vaccines that benefit humans. It is important to remind ourselves that recombinant technology is possible because the genetic code is universal, and the processes of transcription and translation are fundamentally the same in all organisms. Cloning produces genetically identical copies of DNA, cells, or even entire organisms (reproductive cloning). Genetic testing identifies disease-causing genes, and gene therapy can be used to treat or cure an inheritable disease. However, questions emerge from these technologies including the safety of GMOs and privacy issues.
Information presented and the examples highlighted in the section support concepts outlined in Big Idea 3 of the AP® Biology Curriculum Framework. The Learning Objectives listed in the Curriculum Framework provide a transparent foundation for the AP® Biology course, an inquiry-based laboratory experience, instructional activities, and AP® exam questions. A Learning Objective merges required content with one or more of the seven Science Practices.
Big Idea 3 |
Living systems store, retrieve, transmit, and respond to information essential to life processes. |
Enduring Understanding 3.A |
Heritable information provides for continuity of life. |
Essential Knowledge
|
3.A.1
DNA, and in some cases RNA, is the primary source of heritable information.
|
Science Practice |
6.4
The student can make claims and predictions about natural phenomena based on scientific theories and models.
|
Learning Objective |
3.5
The student can justify the claim that humans can manipulate heritable information by identifying an example of a commonly used technology.
|
Big Idea 3 |
Living systems store, retrieve, transmit, and respond to information essential to life processes. |
Enduring Understanding 3.C |
The processing of genetic information is imperfect and is a source of genetic variation. |
Essential Knowledge
|
3.C.1
Changes in genotype can result in changes in phenotype.
|
Science Practice |
7.2
The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas.
|
Learning Objective |
3.24
The student is able to predict how a change in genotype, when expressed as a phenotype, provides a variation that can be subject to natural selection.
|
The Science Practices Assessment Ancillary contains additional test questions for this section that will help you prepare for the AP exam. These questions address the following standards:
- [APLO 3.13]
- [APLO 3.23]
- [APLO 3.28]
- [APLO 3.24]
- [APLO 1.11]
- [APLO 3.5]
- [APLO 4.2]
- [APLO 4.8]
In addition, content from this chapter is addressed in the AP Biology Laboratory Manual in the following lab(s):
16 Bacterial Transformation