Chapter 12 - DNA Technology and Genomics Flashcards
- Explain how plasmids are used in gene cloning.
Plasmids are used in gene cloning by serving as the vector/gene carrier. Plasmid is isolated and is cut with a restriction enzyme. Targeted gene and plasmid DNA are combined –> recombinant DNA molecules. Recombinant plasmid is taken up by a bacterium through transformation and produces clones.
- Explain how restriction enzymes are used to “cut and paste” D N A into plasmids.
Restriction enzymes have specific recognition sites and is used to cut out a specific gene and the same enzyme is used to cut open a plasmid.
- Explain how a nucleic acid probe can be used to identify a specific gene.
Nucleic acid probe is a short, single-stranded molecule of labeled DNA. Probes can also be complementary sequences to the gene of interest and can detect the gene of interest and bind to them through base pairing.
- Explain how the C R I S P R-Cas9 system is used for gene editing.
Researchers can introduce a segment from a normal gene to the Cas9/guide RNA complex. After Cas9 cuts the target DNA, repair enzymes use the normal DNA as a template to repair the target DNA, fixing potential mutations.
- Explain how different organisms are used to mass-produce proteins of human interest.
Recombinant cells made by DNA technologies are used to manufacture many useful proteins.
- Explain how reverse transcriptase is used to help make genes for cloning.
Reverse transcriptase, an enzyme takes RNA (copy of a gene) and converts it into DNA. This results in cDNA which can be inserted into a vector like a plasmid for cloning.
- Explain how DNA technology has helped to treat, diagnose, and prevent disease.
- Treat: Product made using recombinant cells is human insulin, a hormone that helps regulate the levels of glucose in the blood. This helps people with type I diabetes since insulin must be injected in them daily.
- Diagnose: Through DNA analysis, many inherited diseases like hemophilia and cystic fibrosis can be identified in an individual even before symptoms.
- Prevent: Developing vaccines ( a harmless variant/mutant of a pathogen to stimulate the immune system to build defense against that pathogen.
- Explain how genetically modified organisms (GMOs) are transforming agriculture.
- Number of important crop plants are genetically modified and made for medical use.
- Describe the risks posed by the creation and culturing of GMOs and the safeguards that have been developed to minimize these risks.
- Human safety: There was positive results on animals, but there are of limited value and human studies may be unethical. No study documented health risks in humans from GMO foods.
- Environmental safety: Fear that transgenic plants might pass on their new genes to related species in nearby areas, and disturb the composition of the ecosystem.
- Labelling: GMOs are not required to be labeled.
- Describe the benefits and risks of gene therapy in humans. Discuss the ethical issues that these techniques present.
- Benefits: Used to treat a disease using an alteration of a person’s gene.
- Risks: May harm other cell functions and decrease genetic diversity.
- Ethical issues: How will the gene be built at the right time and place? How can it be performed without harming other cell functions?
- Describe the basic steps of DNA profiling.
- Isolate DNA
- DNA of selected markers is amplified
- The amplified DNA is compared
- Explain how P C R is used to amplify DNA sequences.
PCR can be used to amplify a specific gene by using gene-specific primers that bind to the target gene sequence and initiate DNA replication.
- Explain how gel electrophoresis is used to sort DNA and proteins.
An electric current is applied to the gel, DNA migrates towards the positively charged electrode (DNA is negatively charged). Shorter strands of DNA move more quickly through the gel than longer strands –> fragments are arranged in order size.
- Explain how short tandem repeats are used in D N A profiling.
STRs are short sequences repeated many times in a row. If two people have the same sequences at the same place but one person has a different number of repeats, forensic scientists can compare the tiny fraction of genome that is different.
- Describe the diverse applications of DNA profiling.
Many different things can be found by DNA profiling such as relatives can be found, paternity suits can be settled, and genetic disorders can be tested.
