Chapter 20 Flashcards
(31 cards)
nucleic acid hybridization
the base pairing of one strand of a nucleic acid to the complementary sequence on a strand from another nucleic acid molecule
genetic engineering
direct manipulation of genes for practical purposes
DNA sequencing
determining the complete nucleotide sequence of a gene or DNA segment
DNA cloning
the production of multiple copies of a specific DNA segment
plasmid
a small, circular, double stranded DNA molecule that carries accessory genes separate from those of a bacterial chromosome; in DNA cloning, plasmids are used as vectors carrying up to 10,000 base pairs of DNA
recombinant DNA molecule
a DNA molecule made in vitro with segments from different sources
gene cloning
the production of multiple copies of a gene
cloning vector
in genetic engineering, a DNA molecule that can carry foreign DNA into a host cell and replicate there. cloning vectors include plasmids and bacterial artificial chromosomes (BACs) which move recombinant DNA from a test tube back into a cell, and viruses that transfer recombinant DNA by infection
restriction enzymes
a type of enzyme that recognizes and cuts DNA molecules foreign to a bacterium; the enzyme cuts at specific nucleotide sequences (restriction sites)
restriction site
a specific sequence on a DNA strand that is recognized and cut by a restriction enzyme
restriction fragments
a DNA segment that results from the cutting of DNA by a restriction enzyme
sticky end
a single stranded end of a double stranded restriction fragment
gel electrophoresis
a technique for separating nucleic acids or proteins on the basis of their size and electrical charge, both of which affect their rate of movement thru an electric field in a gel made of agarose or another polymer
polymerase chain reaction (PCR)
a technique for amplifying DNA in vitro by incubating it with specific primers, a heat resistant DNA polymerase, and nucleotides
expression vector
a cloning vector that contains a highly active bacterial promoter just upstream of a restriction site where a eukaryotic gene can be inserted, allowing the gene to be expressed in a bacterial cell; expression vectors are also available that have been genetically engineering for use in specific types of eukaryotic cells
electroporation
a technique used to introduce recombinant DNA into cells by applying a brief electrical pulse to a solution containing the cells; creates temporary holes in the cells’ plasma membranes, thru which DNA can enter
nucleic acid probe
a labeled single-stranded nucleic acid molecule used to locate a specific nucleotide sequence in a nucleic acid sample; molecules of the probe hydrogen-bond to the complementary sequence wherever it occurs; radioactive, fluorescent, or other labeling of the probe allows its location to be detected
in situ hybridization
a technique using nucleic acid hybridization with a labeled probe to detect the location of a specific mRNA in an intact organism
reverse transcriptase polymerase chain reaction (RT-PCR)
a technique for determining expression of a particular gene; uses reverse transcriptase and DNA polymerase to synthesize cDNA from all the mRNA in a sample and then subjects the cDNA to PCR amplification using primers specific for the gene of interest
complementary DNA (cDNA)
a double stranded DNA molecule made in vitro using mRNA as a template and the enzymes reverse transcriptase and DNA polymerase; a cDNA molecule corresponds to the exons of a gene
RNA sequencing (RNA-seq)
a method of analyzing large sets of RNAs that involves making cDNAs and sequencing them
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 and tested for hybridization with samples of labeled cDNA
in vitro mutagenesis
a technique used to discover the function of a gene by cloning it, introducing specific changes into the cloned gene’s sequence, reinserting the mutated gene into a cell, and studying the phenotype of the mutant
gene drive
a process that biases inheritance such that a particular allele is more likely to be inherited than are other alleles, causing the favored allele to spread through the population
