Applications of genetics
- Created by: ava.scott
- Created on: 09-04-15 23:10
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- CLONING
- APPLICATIONS OF GENETICS
- GENE THERAPY
- The Human Genome Project
- determined the order of bases in the human genome.
- identified some genes
- addressed ethical and legal problems.
- improved analytical tools.
- applications of THGP
- comparing patents and identifying mutated genes to healthy genes using gene probes.
- carrier screening
- pre-implanation screening
- forensic testing
- evaluation of the THGP
- Practical uses
- reduce illness and suffereing
- pre-symptomatic testing can lead to discrimination and stigma.
- symptoms can sometimes appear earlier.
- risk of false positive- so people will be anxious without need.
- family testing- your own test may have implications for your family.
- WHAT IS GENE THERAPY?
- treats a genetic disease by replacing copies of a fault gene with copies of a new healthy sequence.
- somatic cell therapy
- replaces genes in affected tissues
- therapeutic not inherited
- both use a vector such as plasmid dna, or virus.
- germ line therapy
- change of gene is inserted into germ-line cells.
- inherited change.
- change of gene is inserted into germ-line cells.
- germ line therapy
- replaces genes in affected tissues
- germ line therapy
- change of gene is inserted into germ-line cells.
- inherited change.
- change of gene is inserted into germ-line cells.
- CYSTIC FIBROSIS
- CAUSE
- Recessive allele of the CFTR gene
- CFTR gene makes protein which transports chloride ions out the cell. This function is stopped in cystic fibrosis.
- causing salts and water to remain in cell.
- so mucus is thick, sticky and viscous.
- causing salts and water to remain in cell.
- changing one amino acid.
- CFTR gene makes protein which transports chloride ions out the cell. This function is stopped in cystic fibrosis.
- Recessive allele of the CFTR gene
- symptoms
- food digestion as mucus blocks the pancreatic duct so enzymes cannot reach the duodenum.
- clogged airways resulting in infections and breathing problems.
- daily treatment
- physio therapeutic chest massage
- large food intake and appetite!
- gene therapy for cystic fibrosis
- LIPOSOMES
- Healthy gene is inserted into a liposome
- which are inhaled via a aerosol
- liposomes are absorbed into epithelial cells of lungs
- healthy gene is expressed via protein synthesus
- liposomes are absorbed into epithelial cells of lungs
- which are inhaled via a aerosol
- Healthy gene is inserted into a liposome
- VIRUS
- virus is rendered harmless by removing harmful genes.
- cultured in epithelial cells with palsmids holding the healthy CFTR gene.
- virus takes up normal gene.
- vrius is isolated and introduced to pateint via inhaler
- virus injects CFTR gene into epithelial cells of the lungs.
- vrius is isolated and introduced to pateint via inhaler
- virus takes up normal gene.
- cultured in epithelial cells with palsmids holding the healthy CFTR gene.
- virus is rendered harmless by removing harmful genes.
- limited success as the effect is shortlived, and there could be an immune response.
- however, does improve quality of life, so useful.
- LIPOSOMES
- CAUSE
- Genetic screening
- tests a child for a faulty gene
- blood test
- amniocentesis
- chlorionic villus sampling
- Genetic counselling
- family members seeking advice concerning the chances of having an effected child.
- helps people make informed decisions about life and offsping.
- Advantages of gene therapy
- improves quality fo life
- informed decision about pregnancy
- reduces harmful alleles in population
- less cost for NHS
- Disadvanatges of gene therapy
- Privacy invasion
- increase number of aborions
- insurance companies may increase rates for those with genetic differences.
- fears of eugenics
- germline- unforeseen consequences for future generations.
- The Human Genome Project
- GENETIC ENGINEERING
- identifying gene
- uses probes:
- containing complementary sequence for the beginning of the gene,
- uses probes:
- isolating gene
- resitrcition endonuclease
- vector is plasmid.
- it carries recombinant DNA.
- restriction enzymes cut the foreign DNA at particular sites .
- forming sticky ends
- complentary sticky ends are produced in the plasmid DNA
- DNA ligae anneals the two ends tOgether.
- forming sticky ends
- Plasmids are taken up by bacteria, and then the gene is expressed via protein synthesis.
- uptake of plamsids by bacteria is very small.
- DNA polymerase converts it to a double strand, to incorporate into a plasmid.
- antibiotic resistant sequences are used to identify bacteria which have recombinant DNA/
- uptake of plamsids by bacteria is very small.
- DNA ligae anneals the two ends tOgether.
- vector is plasmid.
- reverse transcripatse
- an enzyme that makes DNA from mRNA.
- mRNA is extracted from suitable cells.
- reverse transcirptase makes a single DNA strand of the desired gene
- DNA polymerase converts it to a double strand, to incorporate into a plasmid.
- this is good as it misses out introns.
- reverse transcirptase makes a single DNA strand of the desired gene
- resitrcition endonuclease
- advantages of engineering
- a complex protein can be made quickly
- dangerous practice of protein removal from corpses or animals can be eliminated.
- health benefits for those with diseases.
- disadvantages of engineering
- complicated and expensive
- huge genome= difficulty in finding gene
- one protein may require many genes.
- or even genes to synthesis enzymes to make the proetin!
- not all genes can be expressed by bacteria.
- HAZRADS
- Bacteria exchange material readily, so a harmful gene could be produced on a huge scale and affect thousands receiving treatment.
- deliberate use of antibiotic restant genes could result in resistant bacteria on a large scale.
- identifying gene
- GENETIC FINGERPRINTING
- an individuals genetic fingerprint or DNA profile is completely unique.
- introns don't code for polypeptides, but vary between individuals as they are repeated.
- DNA is extracted and cut into fragments by restriction enzymes.
- fragments are separated by electrophoresis.
- DNA is negatively charged.
- small fragments move furthest to the positive terminal.
- fragments are transferred to a nylon membrane and exposed to probes.
- dna fragments not attached to a probe are washed off.
- bands left are original for individual.
- nylon membrabe is exposed to xray film, which is exposed by radioactive probes.
- giving a autoradiograph.
- dna fragments not attached to a probe are washed off.
- PCR and gene amplification
- needs DNA polymerase, nucleotides and primers
- 95°C-
- 55°C
- 70°C
- dna polymerase works fast to make double helix.
- allows primers to join to complementary sequences.
- 70°C
- separates DNA strands
- 55°C
- fragments are separated by electrophoresis.
- USES
- Paternity testing
- foensics
- issues with privacy
- mass amount of information needs to be stored appropriately
- however- many genomes are being stored and recorded, so ensure unbiased record of human genome..
- an individuals genetic fingerprint or DNA profile is completely unique.
- GENETIC MODIFICATION
- GM: HOW
- uses a species of bacetria which attacks plants to cause tumours. bad gene is removed and replaced with useful ones.
- GM: Examples
- herbicide resistant soya beans
- lead to socio-economic and environmental problems.
- FlavrSavr tomatoes. Has complementary gene to the enzyme that breaks down pectin. mRNA strands join, so enzyme isnt made.
- herbicide resistant soya beans
- benefits of GM
- superiro keeping qualities
- increased yield
- plants that grow better when less water/nitrates
- resistant plants results in les use of pesticides.
- problems with gm
- genetyiclly engineered pollen could reach wild plants.
- reducing variation between species.
- reduction in biodiversity.
- reducing variation between species.
- new protein may be harmful to eat.
- antibiotic resistant genes transferred to bacteria in gut.
- farmer shave less choice of crops, so their crops are high susceptible to disease.
- lead to socio-economic and environmental problems.
- genetyiclly engineered pollen could reach wild plants.
- GM: HOW
- GENE THERAPY
- PLANTS
- micropropagation
- remove meristem part of plant with sterile equipment.
- explants alllowed to grow in sterile medium into callus
- callus is cut up and allowed to specialise into plantlets
- plantlets are planted into sterile soil
- via mitosis
- callus is cut up and allowed to specialise into plantlets
- explants alllowed to grow in sterile medium into callus
- remove meristem part of plant with sterile equipment.
- ADVANTAGES for plants
- speed of production as avoid pollination and fertilization process
- large quantities
- of uniform crop
- identical, germ line with a advantageous genes- insect resistanc
- DISADVANTAGES
- easily infected crops if the conditions are not sterile.
- uniformity makes crop very vulnerable to widespread disease
- high mutation rates due to genetic unstability.
- micropropagation
- ANIMALS
- embryonic
- nucleus removed from a donor egg cell (enucleation)
- nucelus taken from a donor somatic cell
- somatic nucleus put into empty egg cell.
- nucleus removed from a donor egg cell (enucleation)
- egg cell treated will chemicals or electric shock to start mitosos
- cell dveelops into embryo and is implanted into surrogate mother.
- somatic nucleus put into empty egg cell.
- advantages for animal cloning
- large quantities
- indentical geneticall advanatgeous organisms.
- disadvantages for animal cloning
- expensive and unrelaible
- inadvertent selection of disadvantageous genes e.g. ageing.
- embryonic
- TISSUE CULTURE
- used to:
- create clones a single identical genetic line
- with desirable characteristics
- e.g. cancer cells for medical research
- create clones a single identical genetic line
- applications
- STEM CELLS
- undiffrentiate cells which can specialised into any type of cell.
- used to make blood vessels, cartilage skin grafts
- patients do not rject the implants as they their own DNA.
- ethics for stem cells
- surplus embryos from IVF are destroyed after stem cells are removed- some people consider this murder?
- benefits may outweigh concerns- could be used to treat alzheimers, parkinsons, and heart disease.
- stem cells can be obtained from bone marrow but less diverse applications and more invasive.
- STEM CELLS
- used to:
- APPLICATIONS OF GENETICS
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