Genetic engineering
61 flashcards covering Genetic engineering for the MCAT Biology & Biochemistry section.
Genetic engineering is the deliberate modification of an organism's DNA to introduce new traits, remove unwanted ones, or enhance existing characteristics. This process often involves techniques like cutting and pasting genes using enzymes, inserting DNA into vectors, or employing tools such as CRISPR-Cas9 for precise edits. It's a cornerstone of modern biotechnology, enabling advancements in medicine, such as gene therapy for diseases, and agriculture, like developing drought-resistant crops, making it essential for understanding real-world applications.
On the MCAT, genetic engineering appears in Biology and Biochemistry questions that assess your grasp of molecular techniques, ethical considerations, and experimental applications. Expect multiple-choice questions on processes like recombinant DNA, gene expression regulation, or the risks of genetic modifications, with common traps including mistaking correlation for causation in outcomes or overlooking regulatory hurdles. Focus on integrating concepts with passage-based scenarios and identifying potential errors in procedures.
A concrete tip: Practice drawing out the steps of gene cloning to solidify your understanding.
Terms (61)
- 01
Recombinant DNA
A molecule of DNA that is artificially created by combining genetic material from different sources, enabling the insertion of specific genes into host organisms for various applications.
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Plasmid
A small, circular piece of DNA that can replicate independently of chromosomal DNA and is commonly used as a vector to carry foreign genes into bacterial cells.
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Restriction Enzyme
An enzyme that recognizes and cuts DNA at specific nucleotide sequences, allowing scientists to isolate and manipulate genes for cloning and genetic engineering.
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DNA Ligase
An enzyme that joins DNA fragments by forming phosphodiester bonds, essential for sealing nicks in the DNA backbone during recombinant DNA construction.
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Vector
A DNA molecule used to carry foreign genetic material into a host cell, such as a plasmid or virus, facilitating gene cloning and expression.
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Transformation
The process by which bacterial cells take up foreign DNA from their environment, a key step in introducing recombinant DNA into host organisms.
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Polymerase Chain Reaction (PCR)
A technique used to amplify specific DNA sequences through repeated cycles of denaturation, annealing, and extension, producing millions of copies for analysis.
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Primers
Short, single-stranded DNA sequences that bind to specific target regions on a template DNA, serving as starting points for DNA synthesis in PCR and other techniques.
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Taq Polymerase
A heat-stable DNA polymerase enzyme derived from Thermus aquaticus, used in PCR to synthesize new DNA strands without denaturing during high-temperature cycles.
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Denaturation
The first step in PCR where double-stranded DNA is heated to separate into single strands, allowing access for primers and polymerase.
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Annealing
The step in PCR where primers bind to their complementary sequences on single-stranded DNA, setting the stage for DNA synthesis.
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Extension
The phase in PCR where DNA polymerase adds nucleotides to the primers, extending them to form new DNA strands complementary to the template.
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Gel Electrophoresis
A method that separates DNA fragments based on size by applying an electric current through a gel matrix, allowing visualization of DNA bands.
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Agarose Gel
A porous gel matrix made from agarose that is used in electrophoresis to separate nucleic acids by size, with smaller fragments migrating farther.
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Southern Blotting
A technique that detects specific DNA sequences by transferring DNA fragments from a gel to a membrane and hybridizing them with a labeled probe.
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Probe
A labeled single-stranded DNA or RNA sequence that is complementary to a target sequence, used to detect specific genes in blotting techniques.
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Hybridization
The process where complementary single-stranded nucleic acids bind to form double-stranded molecules, crucial for detecting specific sequences in genetic analysis.
- 18
CRISPR-Cas9
A precise gene-editing tool derived from bacterial immune systems, consisting of a guide RNA and Cas9 enzyme that cuts DNA at specific locations for modification.
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Guide RNA
A synthetic RNA molecule in CRISPR systems that directs the Cas9 enzyme to a specific DNA sequence by base-pairing with the target site.
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Cas9 Enzyme
A protein in the CRISPR system that acts as molecular scissors, cutting DNA at the site specified by the guide RNA to enable gene editing.
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Gene Knockout
A technique that disrupts a specific gene by introducing mutations or deletions, often using CRISPR, to study gene function by observing the resulting phenotype.
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Gene Knock-in
A method that inserts a new gene or modified sequence into a specific genomic location, allowing for the addition of desired traits or correction of defects.
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Transgenic Organism
An organism that has had a foreign gene incorporated into its genome, resulting in new characteristics, such as pest resistance in genetically modified crops.
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Genetically Modified Organism (GMO)
An organism whose genetic material has been altered through genetic engineering techniques, often to enhance desirable traits like nutritional value or disease resistance.
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Gene Therapy
A medical approach that uses genetic engineering to treat or prevent diseases by introducing, altering, or replacing faulty genes in a patient's cells.
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Viral Vectors
Viruses modified to deliver therapeutic genes into host cells, commonly used in gene therapy to achieve targeted and efficient gene transfer.
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Ex Vivo Gene Therapy
A gene therapy method where cells are removed from a patient, genetically modified in the lab, and then reintroduced into the body.
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In Vivo Gene Therapy
A technique that directly introduces genetic material into the patient's body using vectors, without removing cells beforehand.
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DNA Sequencing
A process that determines the precise order of nucleotides in a DNA molecule, essential for identifying genes and mutations in genetic engineering.
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Sanger Sequencing
A method of DNA sequencing that uses dideoxynucleotides to terminate DNA synthesis at specific points, producing readable fragments for gene analysis.
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Next-Generation Sequencing
High-throughput sequencing technologies that rapidly sequence entire genomes or large DNA sets, advancing applications in genetic engineering and personalized medicine.
- 32
Reverse Transcription PCR (RT-PCR)
A variation of PCR that first converts RNA into complementary DNA using reverse transcriptase, used to detect and quantify RNA expression levels.
- 33
Quantitative PCR (qPCR)
A real-time PCR technique that measures the amount of amplified DNA during each cycle, allowing quantification of gene expression or pathogen levels.
- 34
RNA Interference (RNAi)
A biological process where RNA molecules inhibit gene expression by targeting and degrading specific mRNA, harnessed in genetic engineering to silence genes.
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siRNA
Small interfering RNA molecules that trigger the degradation of complementary mRNA, used in research and therapy to knock down specific gene expression.
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Microarray
A tool that simultaneously measures the expression levels of thousands of genes by hybridizing labeled cDNA to a grid of DNA probes on a chip.
- 37
Site-Directed Mutagenesis
A technique that introduces specific mutations into a DNA sequence, often using PCR, to study protein function or create modified genes.
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Homologous Recombination
A natural DNA repair process exploited in genetic engineering to exchange genetic material between similar sequences, enabling precise gene targeting.
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Non-Homologous End Joining
A DNA repair mechanism that directly ligates broken ends, which can be used in CRISPR to create insertions or deletions at target sites.
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Off-Target Effects
Unintended alterations at sites other than the intended target in gene editing, a potential risk in techniques like CRISPR that must be minimized.
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Expression Vector
A vector designed to promote the transcription and translation of inserted genes in host cells, often including promoter sequences for high-level expression.
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Reporter Gene
A gene linked to a regulatory sequence of interest that produces a detectable signal, such as fluorescence, to monitor gene expression in experiments.
- 43
Fusion Protein
A hybrid protein created by joining two or more genes, used in genetic engineering to combine functions, like adding a tag for protein purification.
- 44
Bioinformatics
The use of computer software and algorithms to analyze biological data, such as DNA sequences, in genetic engineering for tasks like gene prediction.
- 45
Ethical Considerations
Issues in genetic engineering involving potential risks, consent, and societal impacts, such as the moral implications of editing human embryos.
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DNA Fingerprinting
A technique that analyzes unique patterns in an individual's DNA, using methods like PCR and electrophoresis, for identification in forensics.
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STR Analysis
A method that examines short tandem repeats in DNA to create a genetic profile, widely used in paternity testing and criminal investigations.
- 48
RFLP
Restriction Fragment Length Polymorphism, a variation in DNA fragment sizes after restriction enzyme digestion, used for genetic mapping and identification.
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Zinc Finger Nucleases
Engineered proteins that bind and cut specific DNA sequences, offering a targeted approach to gene editing before CRISPR became prominent.
- 50
TALENs
Transcription Activator-Like Effector Nucleases, customizable proteins that create double-strand breaks at precise genomic locations for gene modification.
- 51
Delivery Methods
Techniques for introducing genetic material into cells, such as electroporation or viral vectors, critical for the success of gene therapy and editing.
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Insulin Production
An application of genetic engineering where the human insulin gene is inserted into bacteria to produce the hormone for diabetes treatment.
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Vaccine Development
Using genetic engineering to create recombinant vaccines, like inserting viral genes into harmless vectors to stimulate immune responses.
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Stem Cell Engineering
Modifying stem cells through genetic techniques to differentiate into specific tissues, aiding in regenerative medicine and disease modeling.
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Cloning
The process of creating identical copies of DNA fragments, cells, or organisms, such as through somatic cell nuclear transfer as in Dolly the sheep.
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Conjugation
A bacterial process where DNA is transferred between cells via direct contact, sometimes used in genetic engineering to move plasmids.
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Transduction
The transfer of genetic material from one bacterium to another by a virus, a natural mechanism that can be adapted for engineering purposes.
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Promoter
A DNA sequence that initiates transcription of a gene, crucial in genetic engineering for controlling when and where a gene is expressed.
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Antibiotic Resistance Gene
A selectable marker gene included in vectors that allows only transformed cells to survive in the presence of antibiotics, aiding in cloning.
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Epigenetic Editing
Modifying epigenetic marks on DNA to alter gene expression without changing the sequence, an emerging area in genetic engineering for therapy.
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Synthetic Biology
The design and construction of new biological parts, devices, or systems, building on genetic engineering to create novel functions in organisms.