DNA Technology Flashcards
plants that have been genetically engineered to contain specific genes from other plants or even from animals or bacteria.
GM plants
Technique where individuals can be positively identified from just a small sample of their DNA.
DNA fingerprinting
These are actions that have the potential not only to cure a genetic disease in the individual being treated but to prevent the occurrence of that genetic disease in all of his or her future descendants.
Recombinant DNA technologies
DNA from one species can be inserted into the genome of another species, producing
transgenic organisms
Nearly all of the current commercially important GM plants contain genes that either ______________ or that make the plant __________________
allow the plant to produce its own insecticide; resistant to one of the most common herbicides
Steps in Dna sequencing
- extract a fragment of DNA from an organism, induce replication of that DNA fragment, and place millions of identical copies of the fragment into a test tube. add primers, four nucleotides, enzyme that facilitates addition of nucleotides
- the strands of new DNA are placed on a column (or a flat slab) of gel and subjected to a process called gel electrophoresis.
- Finally, a laser scans the gel, reading the locations of the four different fluorescent labels. 3 The result is a graphic display of the labeled nucleotides in the new strands, arranged in order by the sizes of the strands.
Manipulation of the genetic makeup of cells or
whole organisms,
genetic engineering
short single-stranded pieces of DNA that bind to one end of each DNA fragment in the test tube.
Primers
because synthesis always stops as soon as a modified nucleotide is added, What happends?
the final result is a mixture of pieces new stands of DNA of varying lengths, each ending with a single modified (and fluorescently-labeled) nucleotide.
creates an electrical field that causes the DNA strands to migrate through the gel. Smaller strands move more quickly through the gel than larger strands.
gel electrophoresis.
can then be easily calculated on the basis of the known complementary base pairing in DNA.
The sequence of the nucleotides in the original unknown fragment of DNA
What is the goal of recombinant DNA technology?
transfer pieces of DNA (and the genes the DNA contains) from one organism into another.
Most commonly, it is used to insert specific genes (including human genes) into bacteria so that the bacteria can be induced to produce useful protein products.
Recombinant dna technology
naturally occurring enzymes in some bacteria that break the bonds between specific neighboring base pairs in a DNA strand.
Restriction enzymes
There are many different restriction enzymes in nature, but the most useful for recombinant DNA technology are those that make their cut in
palindromic nucleotide sequences
enzymes that bind fragments of DNA back together after the restriction enzymes have cut them.
Dna ligase
small, circular, selfreplicating DNA molecules found in bacteria.
Plasmid
Plasmids are not part of the normal bacterial chromosome, but they are important to the bacterium because
they contain certain genes needed for bacterial replication.
Plasmids are useful to scientists because
they can be extracted from a bacterium, made to take up (combine with) a foreign piece of DNA of interest, and then reinserted back into a bacterium.
technique for producing recombinant DNA using human DNA:
- Isolate DNA plasmids and the human DNA of interest.
- Cut both DNAs with the same restriction enzyme.
- Mix the human DNA fragments with the cut plasmids.
- Add DNA ligase to complete the connections.
- Introduce the new plasmid into bacteria.
- Select the bacteria containing the human gene of interest and allow them to reproduce.
The restriction enzyme cuts the DNA of interest and the plasmid DNA only at specific palindromic nucleotide sequences, leaving
single-stranded ends that will match up with each other.
The DNA fragments begin to join together with the plasmids by
complementary base pairing of the single-stranded cut ends of the fragments.
What must first be identified and isolated before cloning the bacteria (and the human genes they are carrying) in large numbers?
the bacteria that are carrying the gene of interest
If the gene (and its protein product) is present in the bacterial colony, the antibody will bind to
The protein and the bacterial colony of interest can be identified