Describe applications of DNA technology, including gel electrophoresis, DNA fingerprinting, recombinant DNA, and genetically modified organisms, and evaluate their benefits and concerns (TEKS Biology, Reporting Category 2; cause and effect; structure and function).

What this topic is asking

The Biology TEKS ask you to describe applications of DNA technology and to evaluate their benefits and concerns. For STAAR Reporting Category 2 you need to recognize the main tools (gel electrophoresis, DNA fingerprinting, recombinant DNA, and genetically modified organisms), what each does, and how to weigh their advantages against their risks. This is a cause-and-effect and structure and function topic, and it often appears as a scenario asking you to identify a technology and judge its use.

Reading and comparing DNA

This banding pattern is the basis of DNA fingerprinting, comparing the DNA pattern of different samples. Because each person's DNA pattern is essentially unique (except identical twins), DNA fingerprinting is used in forensics (matching a sample to a suspect), in paternity testing, and in identifying remains. On STAAR, a gel diagram is often shown and you are asked which samples match.

Changing DNA: recombinant DNA and GMOs

Other examples include crops engineered to resist pests or to tolerate drought, and bacteria engineered to make medicines or break down pollutants. Genetic engineering differs from selective breeding: selective breeding works slowly over generations using existing variation, while genetic engineering directly inserts or alters a specific gene, often moving it between species.

Weighing benefits and concerns

The TEKS ask you to evaluate these technologies, which means giving both sides:

• Benefits. Reliable supplies of medicines (insulin, vaccines), higher crop yields, pest and disease resistance, identifying criminals and freeing the innocent, and diagnosing genetic disorders.
• Concerns. Possible effects of modified organisms on ecosystems and biodiversity, ethical questions about changing genes, concerns about who controls and can afford the technology, and questions about long-term safety.

A good evaluation names a specific benefit and a specific concern rather than saying simply that biotechnology is "good" or "bad."

Try this

Q1. State what gel electrophoresis separates DNA fragments by, and name one use. [2]

• Cue. By size (smaller fragments travel farther); used in DNA fingerprinting for forensics or paternity testing.

Q2. Describe one benefit and one concern of producing a genetically modified crop. [2]

• Cue. Benefit: higher yield or pest/disease resistance. Concern: possible effects on ecosystems or biodiversity, or ethical and access concerns.