Chapter 20 Vocabulary
- Bacterial Artificial Chromosome (BAC)
- An artificial version of a bacterial chromosome that can carry inserts of 100,000 to 500,000 base pairs.
- Biotechnology
- The manipulation of living organisms or their components to produce useful products.
- cDNA Library
- A limited gene library using complementary DNA. The library includes only the genes that were transcribed in the cells examined.
- Clone
- (1) A lineage of genetically identical individuals or cells. (2) In popular usage, a single individual organism that is genetically identical to another individual. (3) As a verb, to make one or more genetic replicas of an individual or cell.
- Cloning Vector
- An agent used to transfer DNA in genetic engineering. A plasmid that moves recombinant DNA from a test tube back into a cell is an example of a cloning vector, as is a virus that transfers recombinant DNA by infection.
- Complementary DNA (cDNA)
- A DNA molecule made in vitro using mRNA as a template and the enzyme reverse transcriptase. A cDNA molecule therefore corresponds to a gene, but lacks the introns present in the DNA of the genome.
- Denaturation
- In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. In DNA, the separation of the two strands of the double helix. Denaturation occurs under extreme conditions of pH, salt concentration, and temperature.
- DNA Fingerprint
- An individual’s unique collection of DNA restriction fragments, detected by electrophoresis and nucleic acid probes.
- DNA Ligase
- A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3’ end of a new DNA fragment to the 5’ end of a growing chain.
- DNA Microarray Assay
- A method to detect and measure the expression of thousands of genes at one time. Tiny amounts of a large number of single-stranded DNA fragments representing different genes are fixed to a glass slide. These fragments, ideally representing all the genes of an organism, are tested for hybridization with various samples of cDNA molecules.
- Electroporation
- A technique to introduce recombinant DNA into cells by applying a brief electrical pulse to a solution containing cells. The electricity creates temporary holes in the cells’ plasma membranes, through which DNA can enter.
- Expression Vector
- A cloning vector that contains the requisite prokaryotic promoter just upstream of a restriction site where a eukaryotic gene can be inserted.
- Gel Electrophoresis
- The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.
- Gene Cloning
- The production of multiple copies of a gene.
- Gene Therapy
- The alteration of the genes of a person afflicted with a genetic disease.
- Genetic Engineering
- The direct manipulation of genes for practical purposes.
- Genetically Modified (GM) Organism
- An organism that has acquired one or more genes by artificial means; also known as a transgenic organism.
- Genomic Library
- A set of thousands of DNA segments from a genome, each carried by a plasmid, phage, or other cloning vector.
- Genomics
- The study of whole sets of genes and their interactions.
- Human Genome Project
- An international collaborative effort to map and sequence the DNA of the entire human genome.
- In Vitro Mutagenesis
- A technique to discover the function of a gene by introducing specific changes into the sequence of a cloned gene, reinserting the mutated gene into a cell, and studying the phenotype of the mutant.
- Linkage Map
- A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.
- Nucleic Acid Hybridization
- Base pairing between a gene and a complementary sequence on another nucleic acid molecule.
- Nucleic Acid Probe
- In DNA technology, a labeled single-stranded nucleic acid molecule used to tag a specific nucleotide sequence in a nucleic acid sample. Molecules of the probe hydrogen-bond to the complementary sequence wherever it occurs; radioactive or other labeling of the probe allows its location to be detected.
- Physical Map
- A genetic map in which the actual physical distances between genes or other genetic markers are expressed, usually as the number of base pairs along the DNA.
- Polymerase Chain Reaction (PCR)
- A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.
- Proteomics
- The systematic study of the full protein sets (proteomes) encoded by genomes.
- Recombinant DNA
- A DNA molecule made in vitro with segments from different sources.
- Restriction Enzyme
- A degradative enzyme that recognizes and cuts up DNA (including that of certain phages) that is foreign to a bacterium.
- Restriction Fragment
- DNA segment resulting from cutting of DNA by a restriction enzyme.
- Restriction Fragment Length Polymorphisms (RFLPs)
- Differences in DNA sequence on homologous chromosomes that can result in different patterns of restriction fragment lengths (DNA segments resulting from treatment with restriction enzymes); useful as genetic markers for making linkage maps.
- Restriction Site
- A specific sequence on a DNA strand that is recognized as a cut siteby a restriction enzyme.
- RNA Interference (RNAi)
- A technique to silence the expression of selected genes in nonmammalian organisms. The method uses synthetic double-stranded RNA molecules matching the sequence of a particular gene to trigger the breakdown of the gene’s messenger RNA.
- Single Nucleotide Polymorphisms (SNPs)
- One base-pair variation in the genome sequence.
- Southern Blotting
- A hybridization technique that enables researchers to determine the presence of certain nucleotide sequences in a sample of DNA.
- Sticky End
- A single-stranded end of a double-stranded DNA restriction fragment.
- Ti Plasmid
- A plasmid of a tumor-inducing bacterium that integrates a segment of its DNA into the host chromosome of a plant; frequently used as a carrier for genetic engineering in plants.
- Yeast Artificial Chromosome (YAC)
- A vector that combines the essentials of a eukaryotic chromosomean origin for DNA replication, a centromere, and two telomereswith foreign DNA.
