Biology vocab chapter 20

To work directly with specific genes, scientists prepare well-defined DNA segments in multiple identical copies by a process called

are small, circular DNA molecules that replicate separately from the bacterial chromosome

Researchers can insert DNA into a plasmid to produce a ______________ ________ _which contains DNA from two different sources

production of multiple copies of a single gene is a type of DNA cloning called

• useful for amplifying genes to produce a protein product for research, medical, or other purposes

A plasmid used to clone a foreign gene is called a

cuts DNA molecules at a specific DNA sequence

The site at which restriction enzymes cut

a restriction enzyme usually makes many cuts in a long DNA molecule yielding…

• The most useful restriction enzymes cut DNA in a staggered way, producing fragments with at least one single-stranded end 

• bond with complementary of these in other fragements and use DNA ligase to seal the bond

What is often used as a cloning vector and why?

• a decives used to separate and visualize the restriction fragments produced

• This technique uses a gel made of a polymer that has microscopic holes of different sizes, through which shorter fragments can travel faster

• can produce many copies of a specific target segment of DNA,

• uses a three step process: heating (denaturing), cooling (annealing), and extension

• The process uses primers, short single-stranded DNA molecules complementary to sequences to either side of the target sequence

• a cloning vector that contains a highly active bacterial promoter

  • used to overcome difference in promoters

• applying a brief electrical pulse to create temporary holes in plasma membranes

  • method of introducing recombinat DNA into eukaryotic cells

complementary molecules of DNA or RNA that can detect mRNA

• uses fluorescent dyes attached to probes to identify the location of specific mRNAs in place in the intact organism

• useful for comparing amounts of specific mRNAs in several samples at the same time

• is used to synthesize a complementary DNA (cDNA) copy of each mRNA in the sample and uses PCR to amplify DNA segaments of interest from the cDNA

• sequence cDNA samples from different tissues or embryonic stages to determine the gene expression differences between them

  • RNAs are isolated, cut into short, similar-sized fragments, converted into cDNAs, and sequenced

  • powerful because:

    • It does not depend on knowing genomic sequences

    • It can measure levels of expression over a wide range

    • Careful analysis provides a wealth of information about expression of a particular gene

• compare patterns of gene expression in different tissues at different times or under different conditions

• specific mutations are introduced into a cloned gene, altering or destroying its function

  • When the mutated gene is returned to the cell, the normal gene’s function might be determined by examining the mutant’s phenotype

• engineer the new allele so that it is favored for inheritance over the wild type allele

can silence gene expression

• Synthetic double-stranded RNA molecules matching the sequence of a particular gene are used to break down or block the gene’s mRNA

• single nucleotide variants, are among the most useful genetic markers

• is a relatively unspecialized cell that can reproduce itself indefinitely, or under certain conditions can differentiate into one or more types of specialized cells

a cell that can generate a complete new organism

embroyonic stem cells that are capable of differentiating into many different cell types

• the manipulation of organisms or their components to make useful products

• the introduction of genes into an afflicted individual for therapeutic purposes 

• is a gene that is transferred from one organism into another

animals that can express a transgene

an individuals uinique set of genetic markers, can be obtained by analysis of tissue or body fluids

• Genetic profiles are currently analyzed using genetic markers

  • are variations in the number of repeats of specific DNA sequences; they are analyzed by PCR and gel electrophoresis