Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA work because _____
|
the fragments will bond to other fragments with complementary single-stranded ends
|
|
DNA used in recombinant DNA techniques is first cut into fragments by _____.
|
restriction enzymes
|
|
"Sticky ends" are very useful in genetic engineering because _____.
|
they provide a site for complementary base pairing so that pieces of DNA can be linked together
|
|
An enzyme that "cuts" DNA at a symmetrical sequence of bases is called _____.
|
restriction enzyme
|
|
Bacteria use restriction enzymes to _____.
|
destroy foreign DNA
|
|
What enzyme could seal a nick in one strand of a double-stranded DNA molecule by creating a sugar-phosphate bond between the adjacent, unjoined nucleotides?
|
DNA ligase
|
|
What two enzymes are needed to produce recombinant DNA?
|
a restriction enzyme and a ligase
|
|
Restriction enzymes leave "sticky ends" when they cut a piece of DNA. The most useful result of this is that the sticky ends allow ____________.
|
the easy insertion of a foreign piece of DNA that has had its ends cut by the same restriction enzyme
|
|
In genetic engineering "sticky ends" refers to _________.
|
short bits of single-stranded DNA left at the end of a DNA molecule cut by a restriction enzyme
|
|
The so-called sticky ends of a plasmid or bacterial chromosome are ____________.
|
unpaired bases produced by a restriction enzyme
|
|
Describe DNA fingerprinting
|
it is a forensic procedure now being utilized to identify individuals; compares the DNA banding patterns of small segments of chromosomes
|
|
What is a nucleic acid probe used for?
|
to identify genes that have been inserted into bacterial plasmids or separated by electrophoresis
|
|
DNA synthesized using an RNA template is called _____.
|
cDNA
|
|
An enzyme that makes DNA from an RNA template is called ____________.
|
reverse transcriptase
|
|
What is the source of the reverse transcriptase used in recombinant DNA technology?
|
retroviruses
|
|
Which arrangement of the following four enzymes represents the order in which they would be used in a typical gene-cloning experiment resulting in the insertion of a foreign gene into a bacterial plasmid? Begin with the gene's mRNA transcript: restriction enzyme, reverse transcriptase, DNA polymerase, DNA ligase
|
reverse transcriptase, DNA polymerase, restriction enzyme, DNA ligase
|
|
What is Southern Blotting?
|
a technique used to study RFLPs
|
|
In recombinant methods, the term "vector" refers to _____.
|
a plasmid or other agent used to transfer DNA into a living cell
|
|
The polymerase chain reaction (PCR) is a useful technique because it can _____.
|
make a large amount of DNA from a tiny amount
|
|
In the polymerase chain reaction (PCR), the sequence of bases in the primers is important because it ___________.
|
determines which segment of the genome will be amplified
|
|
A molecular biologist has isolated a short segment of DNA that she wants to replicate in vitro. First she heats the DNA, which separates the two strands, and then she adds _____, _____, and _____.
|
nucleotides, primers, and polymerase
|
|
Electrophoresis is used to _____.
|
separate fragments of DNA
|
|
In classical mapping studies, genes are located according to distances measured in percent recombination. By comparison, in restriction mapping studies, __________ are located according to distances measured in __________.
|
restriction enzyme recognition sequences ... DNA fragment lengths
|
|
what is a genetic marker?
|
a particular nucleotide sequence whose inheritance can be followed
|
|
Human nerve cells differ from human muscle cells because different sets of genes are expressed; in each type of cell, different genes are transcribed into mRNA and translated into protein. What technique would be the most efficient way to identify the genes that these cells express?
|
DNA microarray assays
|
|
Putting a human gene into the plasmids of bacteria has enabled scientists to _____.
|
use bacteria as "factories" for protein products such as insulin
|
|
briefly describe gene therapy
|
a functioning version of a defective gene is added to the cells of an individual
|
|
True or False: Bacteria normally make insulin
|
false
|
|
A molecular biologist used a virus to introduce a gene coding for a certain human enzyme into mouse cells. Some of the mouse cells were able to make the enzyme, but most of these cells lost the ability to make some other protein—different ones in different cells. What is the best explanation of these results?
|
The virus inserted the enzyme gene into various mouse cell genes.
|
|
DNA fingerprints used as evidence in a murder trial look something like supermarket bar codes. The pattern of bars in a DNA fingerprint shows _____.
|
the presence of various-size fragments of DNA
|
|
Would a rat with rabbit hemoglobin genes be considered a transgenic organism?
|
yes
|
|
Would a bacterium that has received genes via conjugation be considered a transgenic organism?
|
yes...maybe on pluto
(that means no.... on earth) |
|
Why do genetic engineers often insert marker genes into plasmids containing genes of interest?
|
so they will know which bacteria have taken up the plasmid
|
|
So far, using the Ti plasmid as a vector has not resulted in significant increases in the production of grass crops, such as wheat, because _____.
|
the Ti plasmid does not work as a vector for monocots
|
|
Transgenic organisms can be scientifically or commercially useful only if ___________.
|
the inserted ("foreign") gene is expressed in the host organism
|
|
In genetic engineering, the highly active plasmid from Agrobacterium tumefaciens is used to _____.
|
insert genes of interest into plant chromosomes
|
|
bacterial artificial chromosome (BAC)
|
An artificial version of a bacterial chromosome that can carry inserts of 100,000–500,000 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.
|
|
chromosome walking
|
A DNA mapping technique that begins with a gene or other sequence that has already been cloned, mapped, and sequenced and "walks" along the chromosomal DNA from that locus, producing a map of overlapping restriction fragments.
|
|
denaturation
|
For proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. For DNA, the separation of the two strands of the double helix. Denaturation occurs under extreme conditions of pH, salt concentration, and temperature.
|
|
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.
|
|
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.
|
|
invitro 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.
|
|
polymerase chain reaction (PCR)
|
A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.
|
|
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.
|
|
yeast artificial chromosomes (YACs)
|
Yeast artificial chromosomes; vectors that combine the essentials of a eukaryotic chromosome, an origin for DNA replication, a centromere, and two telomeres, with foreign DNA.
|
|
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.
|