Unit 3.5.8 - Gene Technology Flashcards
How is DNA base sequencing carried out nowadays?
Done together in one tube in an automated base sequencer. The tube contains all the modified nucleotides each with a different coloured fluorescent label.
What does gene therapy involve?
Altering the defective genes inside cells to treat genetic disorders and cancer.
Name the three main uses of transformed organisms?
- Agriculture
- Industry
- Medicine.
What three things can be genetically engineered to benefit humans.
- Micro organisms
- Plants
- Animals
What is the name of the two different techniques you can use for gene cloning?
Invitro and Invivo cloning
How can restriction mapping be used to work out if a piece of DNA contains your added DNA fragment.
It will produce a different restriction map.
How does the amount of DNA change for one cycle of PCR?
It doubles.
What DNA do you look at if you want to trace only the female line of descent?
Mitochondrial DNA
What is meant by not all of an organisms genome codes for proteins?
Some of the genome consists of repetitive, non coding sequences.
What is gene cloning?
It is where you make identical copies of a gene.
What are two advantages of using transformed organisms in medicine?
1, Many drugs and vaccines are produced by transformed organisms using recombinant DNA technology.
2. Drugs made using recombinant DNA technology can be produced quickly, cheaply and in large quantities. This can make them more affordable and so make them more available to people.
What is an disadvantage of using transformed organisms in industry.
Some people are worried that the process used to purify proteins could lead to the introduction of toxins into the food industry.
What are two ethical issues surrounding gene cloning?
- could be used in other ways other than medical treatment - treating the cosmetic effects of aging.
- People worry that it can do more harm than good - risk of over expression or it going wrong.
How is electrophoresis carried out in four steps?
- DNA fragments are injected into wells of the gel and covered with a buffer solution that conducts electricity.
- An electric current is applied along the gel.
- DNA is negatively charged so attracted to the positive end of the gel.
4 Short fragments move faster than longer fragments and so they are separated according to length.
How can you use genetic fingerprinting in genetic science?
You can compare sample of DNA collected from crime scenes to DNA from possible suspects to link them to the crime.
What method can be used to make transformed micro organisms?
Invivo cloning.
Why do more people suffer from sickle cell anaemia where malaria is more common?
Carriers are partially protected meaning they are more likely to survive so there is an increase frequency of the sickle call allele in the areas where malaria is common which increases the likelihood of someone carrying two copies of the allele and so there will be more sufferers.
What are four advantages of invivo cloning?
- It can produce mRNA and protein as well as DNA because it is done in the living cell.
- It can produce modified RNA, modified mRNA or modified proteins.
- Larger fragments of DNA can be cloned.
- Relatively cheap method.
How do you identify transformed cell?
Host cells are grown on agar plates and each cell divides and replicates its DNA creating a colony of cloned cells. Transformed cells will produce colonies where all the cells contain the cloned gene and the marker gene so you can use the marker gene to identify the transformed cells.
What is genetic engineering also known as?
Recombinant DNA technology.
What is the place called that restrictive endonuclease cuts the DNA at?
Recognition site.
What is recombinant DNA?
DNA made by joining together DNA from different sources.
What does a band at the same location during genetic fingerprinting show?
The same number of nucleotides in the fragment.
What are the two different types of screening you can do using DNA probes?
Screening for single genes and screening for multiple genes.
What are four advantages of gene therapy?
1, Prolong the life of people with life threatening disorders and cancer.
- Give people with genetic disorders and cancer a better quality of life by easing their symptoms.
- Germ line therapy will allow the carriers of a genetic disorder to conceive a baby without the disease.
- Germ Line therapy will also decrease the number of people that suffer from the genetic disorder or cancer.
What is a primer?
A short piece of DNA that is complimentary to the bases at the start of the fragment you want to copy.
Name five uses of genetic fingerprinting.
- Determine genetic relationships
- Determine genetic variability within a population.
- Forensic Science
- Medical diagnosis
- Animal and Plant breeding.
How can you make transformed animals?
By inserting the gene that codes for a desirable characteristic into an animal embryo.
What are antiglobalisation activists against?
Large bio technology companies who control the use of genetic engineering becoming bigger and more powerful.
What is invivo cloning?
Where the gene copies are made within a living organism, as the organism grows and divides it replicates it’s DNA creating multiple copies of the gene.
What are the two types of gene therapy?
Somatic therapy and germ line therapy.
How do you read the DNA base sequence from the gel produced at the end of the chain termination method?
Read the bands from the bottom up, each band represents one more base you have added.
What is the advantageous effect of sickle cell anaemia?
The carriers are partially protected from malaria.
How do you make a DNA probe to screen for clinically important genes?
The gene you want to screen is sequenced. PCR is then used to make multiple copies of part of the gene and these are the probes.
What are the host cells during invivo cloning?
Bacteria cells
When are marker genes inserted into the vectors?
At the same time as the gene to be cloned.
What is a DNA microarray?
A glass slide with microscopic spots of different DNA probes attached to it.
Which method of gene therapy you use depends on?
Whether the disorder is caused by a mutated dominant allele or two mutated recessive alleles.
What are six disadvantages of gene therapy?
- The body could identify the vector as foreign bodies and start an immune response against them.
- An allele could be inserted into the wrong place in the DNA causing more problems.
- An inserted allele could be over expressed producing too much of a missing protein.
- Disorders caused by multiple genes will be difficult to treat with this technique.
- Somatic therapy may have a short term effect
- People may have to undergo multiple treatments with somatic therapy.
If a gene is too long to be sequenced what can you use first to make smaller fragments?
Restriction mapping
What are the three ways that DNA fragments can be produced?
Reverse transcriptase, Restriction endonuclease and PCR.
How many primers do you need for one cycle of PCR and why?
Two , one for each strand.
Why can gene technologies now be done on a larger scale?
The techniques are often automated and more cost effective.
What is the two main uses of genetic screening in medicine?
Diagnosing genetic disorders and deciding treatment options.