Manipulating genomes Flashcards
Electrophoresis
the DNA is placed at the cathode and due to its negative charge it will travel through the agrose gel to the anode. The smaller fragments of DNA will travel faster and the DNA will be seperated in size order - make sure it is timed. A dye is then added to the buffer solution and the complimentary sequence of DNA can be read
Resolution on gel sufficient to one nucleotide base
How does the diameter of the bronchioles become reduced
Extra mucous production
Inflammation
Restricts air flow
PCR
Amplifies a short piece of DNA which produces a range of DNA at different lengths
DNA restriction enzymes
To cut plasmids / vectors
To cut (genome DNA) into smaller fragments
Why does the genome need to be fragmented before sequencing
Genome to large
Accuracy better with smaller fragments
Divide job over time
How would a plant with polyploidy appear
Larger in size
How does the phylogenetic approach to classifying species differ from the biological species concept
No need to test for interbreeding
Can apply to organisms that reproduce asexually
Can apply to extinct organisms
Common ancestor
Enzyme that cuts DNA
Restriction endonuclease
A vector to introduce foreign DNA into bacteria
Plasmid
BAC
Bacteriophage
A vector to introduce foreign DNA into plant cells
Plasmid
Virus
Agrobacterium tumefaciens
A vector to introduce foreign DNA into animal cells
Plasmid
Recombinant DNA
DNA molecule treated in vitro by joining DNA with a vector molecule of DNA
DNA Polymerase
catalyses formation of double stranded DNA from a single stranded DNA template
DNA Ligase
catalayses formation of phosphodiester bonds between sugar and phosphate groups of DNA backbone strands
Assess the potential danger to natural habitats of cultivating transgenic crops
For example, the study/trial shows that these are not likely to survive if they escape into the wild; most extinct within four years; all population sizes shrunk within first year; some people fear that genes for herbicide resistance could transfer to weeds; probably unlikely as genes do not normally transfer from crop plants to wild weed plants; they are different species so cross pollination not likely/pollen not compatible; even if hybrids were produced, they are likely to be infertile (contrast this with garden escapes, such as rhododendron or Japanese knotweed that are invasive and destructive)
Ethical implications of growing GM crops
For example, need to produce more food to meet demands of growing population; cannot just keep using more fertiliser and pesticides; need to make crops resistant to drought/flood/higher temperatures; as well as to diseases/pests; also need nutritionally enhanced crops; suitable examples, such as Golden RiceTM, bananas with more zinc; pesticide resistance could eliminate need for pesticides and exposure of sprayers to the pesticides; concerns about effects of GM crops on biodiversity; but they have been grown in US for 20 years and no apparent loss of biodiversity; no obvious ill health consequences to humans from eating them have been seen so far; suggestions GM causes reduction in honey bee populations; but this unlikely to be the case as bee populations are dwindling in UK and no commercially grown GM here; more likely to be (nicotinoid) pesticides; accept all valid points in balanced argument.
How are viruses used as vectors in gene therapy
Virus genes/genome knocked out or altered; so not virulent/cannot cause infection; insert gene to be delivered within the protein coat of virus; can be injected or breathed in in vivo; can be injected into extracted cells in vitro and then altered cells placed back into patient; viruses dock with receptors on host cell plasma membranes and enter the cell, so can carry in the gene; many viruses insert their genes into host genome.
Why does treatment for cystic fibrosis need to be repeated
Treatment for cystic fibrosis needs to be repeated as epithelial cells lining the airways are replaced every 10-14 days; therefore new cells will need to the genes to be inserted
