Application of reproduction and genetics Flashcards
(35 cards)
What is the human genome project?
Aimed to sequence the whole human genome
Improved knowledge and understanding of genetic disorders and improve diagnosis and treatment
Used sanger sequencing (sequenced sections)
Specific human genome project aims
Identify all genes in the human genome and which chromosome each is on
Determine the sequence of 3 billion base pairs
Improve data analysis tools
Findings of Human genome project
20,500 genes
More repeated segments of DNA
Less than 7% of protein families were specific to vertebrates
What was the 100K Genome project?
Studied the genomes of 100K people to study genetic variation in the UK
Uses NGS which is faster
100K genome project aims
Create an ethical, transparent programme based on consent
Set up NHS genomic service
Develop a UK genomics industry
Ethical issues with genome sequencing
Ownership of information (e.g. insurance companies should not profit of info)
Screening embryos can lead to concerns over choosing certain alleles for a ‘designer baby’
Storage of genomic information
Advantages of genome sequences
Can tell if DNA is mutated via comparison
May be possible to screen for Alzheimers/cancer
Embryos made in IVF can be screened for genetic diseases (cystic fibrosis, hungtintons, thalassaemia)
Genetic counselling for people with screened genetic problems
How has the genome sequencing of mosquitoes been helpful?
Can study the cause of insecticide resistance
Develop new chemicals that can reduce the population
Prevents the spread of malaria
Gene can be written into the genome to stop spread
How has genome sequencing helped control the spread of Plasmodium parasite?
Sequencing the genome allows scientists to develop more effective drugs to treat the disease
Can combat drug resistance
Stages of DNA fingerprinting (basic)
1) Isolate unique DNA
2) Amplify DNA w/ PCR
3) Separate DNA by gel electrophoresis
How is DNA isolated in DNA fingerprinting?
STRs= short tandem repeats (repeated nucleotides), in introns, are inherited
Number of repeats is unique to individual
More repeats= longer fragments
STRs are cut out using
PCR process
1)STRs replicate and are heated to 95 degress which breaks H binds and separates strands
2)Cooled to 50-60 degrees to anneal primers to complementary DNA
3)Heated to 70 degrees to allow Taq polymerase to bind to the primers
4)Taq polymerase adds nucleotides in 3’—>5’ direction, then maintained at 70 degrees
Gel electrophoresis process
1) Amplified STR fragments are loaded into wells, different wells for each individual as well as a reference sample (DNA of known lengths)
2) Electrical current is applied and DNA fragments move towards the positive electrode due to negative phosphate group
3) Smaller fragments move easily through the gel
4) Electrofluorescent/ radioactive marker used to make DNA visible
Uses of DNA fingerprinting
Paternity testing
Identification of siblings/ checking for identical twins
Identification of relatives (immigration)
Forensic use to rule out suspects
Identify closely related organism (classification)
Advantages of DNA fingerprinting
Non-invasive
Small samples
Exonerate the falsely accused
Disadvantages of DNA fingerprinting
Civil liberty issues/privacy
Safe storage issues
Mishandling can lead to wrongful convictions
Genetic engineering process
1) Isolate the gene (2 methods)
A= Use restriction endonucleases to produce sticky ends due to unpaired bases
B= Use reverse transcriptase on mRNA of gene of interest to produce a single strand of complementary DNA, apply DNA Polymerase and free nucleotides–> double strand, Use restriction endonucleases–> double strand w/ sticky ends, no introns
2) Cut plasmid (w/ antibiotic resistant gene)out of cell w/ same restriction enzymes used for the gene for complementary sticky ends, DNA ligase is used to anneal the plasmid and the gene= recombinant plasmid
3) Place in a solution w/ bacteria and some will take up a plasmid
4) Serial dilution and grow on agar containing antibiotics, colonies contains on transgenic bacteria as these are antibiotic resistant
Transgenic meaning
An organism w/ a gene from another cell/ organism
What are marker genes?
Help identify transgenic bacteria
X-Gal, white=plasmid
Blue= no plasmid
Issues with only using restriction endonucleases in isolating the gene
Need knowledge of gene and bases around
Cutting gene into fragments
Will include introns that need removing
Issues with genetically modifying crops
Pest resistance
Antibiotic resistant marker genes
Adverse health affects
Economic concerns
Advantages of GM crops
High yield
Pesticide reduction
Improved food
Pharming
Disease resistant
Issues w/ GE bacteria
Fast, high yield, produces exact replica, could spread antibiotic resistance to pathogenic bacteria, DNA fragments could transfer/ activate oncogenes
What is gene therapy?
Inserting functional allele to counteract a non-functional allele
