Topic 7.3 Gene technology Flashcards
Define genetic modification
the insertion of genes from one organism into the genetic material of another organism or changing the genetic material of an organism
What is recombinant DNA?
new DNA produced by genetic engineering technology that combines genes from the DNA of one organism with the DNA of another organism
What’s reverse transcriptase?
the enzyme used to make artificial copies of a desired gene by taking an mRNA molecule transcribed from the gene and using it to produce the correct DNA sequence
What is complementary DNA, cDNA?
DNA which can act as an artificial gene. made by reversing the transcription process from mRNA using reverse transcriptase
What is a sticky end?
the area of base pairs left longer on one strand of DNA than the other by certain restriction endonucleases, making it easier to attach new pieces of DNA
Define replica plating
the process used to identify recombinant cells that involves growing identical patterns of bacterial colonies on plates with different media
What are gene guns?
used to produce recombinant DNA by shooting the desired DNA into the cell at high speed on minute gold or tungsten pellets
Define liposome wrapping
a technique used to produce recombinant DNA that involves wrapping the gene to be inserted in liposomes ,which fuse with the membrane and can pass through to deliver the DNA into the cytoplasm
What’s microinjection?
also called DNA injection and is a technique for producing recombinant DNA that involves injecting DNA into a cell through a very fine micropipette
Describe the process of using bacterial plasmids as DNA vectors
- isolate the required gene using restriction endonucleases
- cut the plasmid with restriction endonucleases
- join the plasmid and the gene with DNA ligase to produce recombinant DNA
- insert the gene into the vector
- remove existing plasmids from host bacterial cell
- use vector to introduce gene into host cell
- the modified bacterium will now produce a different protein as the new gene is expressed and causes synthesis of the protein
What are transgenic animals?
animals that have had their DNA modified using gene technology, so that at least some of their cells contain recombinant DNA
Why does recombinant DNA technology work?
because the genetic code is universal, and therefore transcription and translation occur by the same mechanism and result in the same amino acid sequence across organisms
Give ways in which recombinant DNA can be inserted into other cells
- using viruses
- liposome wrapping
- microinjection
Summarise the process of inserting a vector into a host cell
the bacterial host cells are mixed with the vectors in an ice-cold solution, then heat shocked to encourage the cells to take up the vectors. the cells can then be grown and the DNA fragment will be cloned
Describe a way to identify recombinant cells
marker genes inserted into plasmids at the same time as DNA fragments (antibiotic resistant genes) the transformed cells are placed on an agar plate with antibiotics, so only the ones who successfully took up the vector will grow
