Manipulating genomes Flashcards
What is the purpose of DNA sequencing?
Working out the sequence of bases in a strand of DNA
What is bioinformatics?
The development of software and computingtools needed to organise and analyse raw biological data
What is computational biology?
Using raw data to build theoretical models of biological systems
What is a genome?
All the genetic material of an organism
What is genomics?
The branch of biology concerned with evolution, structure, function, and mapping of genomes
What is synthetic biology?
The redesign of existing natural biological systems
How can the comparison of many human genomes help the understanding of disease?
Show the patterns of disease inherited by people and diseases which people may be vulnerable to
Why might scientists want to analyse the genomes of pathogens?
- To find out the source of an infection
- To identify antibiotic resistant strains of bacteria
- To track the progress of an outbreak
- To identify regions of pathogen genomes that may be useful targets for new drugs
How can DNA barcoding allow for the identification of species?
- Sections of the genome are common to all species but the sequences vary between them
- This section of DNA can be compared
How can DNA sequencing allow scientists to identify the evolutionary relationships between species?
- DNA sequences of different organisms can be compared
- Due to DNA mutation rate scientists can calculate how long ago species diverged from a common ancestor
What can DNA profiling be used for?
- Identifying individuals at risk of developing certain diseases
- Identifying perpatrators of crimes
What is the process of Southern blotting?
- Gel electrophoresis is completed
- Nitrocellulose paper is placed against the gel
- Paper placed in buffer solution with DNA probes which hybridise
- Autoradiography is completed
What does PCR stand for?
Polymerase Chain Reaction
What is added to a DNA sample in PCR?
- DNA nucleotides
- DNA polymerase
- 3’ primers
What temperatures is PCR cycled through?
- 95º
- 55º
- 72º
Why is the sample heated to 55º in PCR?
Allows the primer to bind to the DNA
Why is the sample heated to 95º in PCR?
Hydrogen bonds between strands break
Why is the sample heated to 72º?
It is the optimum temperature for taq polyermase
How is an insulin recombinant plasmid formed?
- mRNA is isolated and converted to cDNA using reverse transcriptase
- Plasmid is cut with a restriction so the sticky ends match the cDNA
- Plasmid and gene are combined with DNA ligase
How can recombinant plasmids be inserted into bacteria?
- Electroporation or
- Place cells and plasmid in Ca2+ and increase the temperature
Which bacteria is used to produce GM plants?
A. tumefaciens
What are the positive impacts of genetic engineering of pathogens?
- Useful substances can be produced cheaply, reliably and in large quantities
- Used for research into medical treatments
- Living resource of sequences DNA fragments for future use
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What are the negatives of genetic engineering of pathogens?
- pathogens could be modified to make them more virulent (could be used as a biological weapon)
- Antibiotic resistant bacteria could escape from labs
What are the positives of engineering soya beans with herbicide and insect resistance?
- reduces need for pesticides
- targets effect on pesticides that damage the crop
- increases crop yields
What are the negatives of engineering soya beans with herbicide and insect resistance?
- pests may develop resistance
- new seeds must be used each year
- genes for herbicide resistance could spread and create superweeds
- encourages overuse of herbicides
- killing insects interupts the food chain
What are the advantages of genetic engineering over artificial selection?
- Very quick, desired genes can be formed in one experiment
- Large scope for genetic changes
- Small space needed
What are the advantages of artificial selection over genetic engineering?
- Limited technology is needed
- Low cost
- Technology has been used for 1000’s of years
What are the postitives of GM crops?
- pest resistant crops increase yield and reduce amount of pesticide used
- crops with an extended shelf life help to reduce food waste
- nutritional value of crops can be increased
- plants could be used to produce human medicines
What are the negatives of GM crops?
- non-pests and insect predators may be damaged by toxins in GM plants
- insects may become resistant to pesticides
- transferred genes might spread to wild populations
- people may be allergic to different proteins made in GM crops
What are the issues with patenting GM crops?
- Limits the avaliablility of new developments
- Those in most need may not be able to afford it
Give an example of GM farm animals
- Swine fever resistant pigs; fewer animals contract the disease so higher yield and better animal welfare
What is pharming?
Using animals to produce human medicines
Give 2 examples of pharming
- Animal models for disease
- Production of human proteins in milk e.g. antibodies
What is gene therapy?
Treating a disease by targeting the faulty gene responsible for the disease
What is somatic cell gene therapy?
Gene therapy which targets cells of the body
What is germ line gene therapy?
Gene therapy which targets gametes and undifferentiated embryonic cells
What are the disadvantages of somatic cell therapy?
- It is only a temporary solution
- Faulty allele can be passed onto children
- Treatment must be repeated
What are the disadvantages of germ line cell therapy?
- Impact on germ cells are unknown
- Human rights of the child would be violated
- Raises many ethical questions e.g. designer babies
What diseases has somatic cell therapy successfully treated?
- Retinal disease
- Haemophilia
- Leukemia
What are the potential risks of gene therapy?
- New gene may be inserted into the wrong place in DNA
- overexpression of missing protein
- DNA could accidentally be introduced into gametes
- Immune system complications
