6.1.3 Manipulating Genomes Flashcards
What is genetic fingerprinting?
DNA profiling identifies unique DNA patterns in individuals
Helps identification in forensics
Identifies family relationships (paternity tests)
What are variable number tandem repeats (VNTR)?
Present in most eukaryotes. Show most variation between individuals of same species. Non coding sections of dna. Have extensive variability in sequence and length.
Srts are shorter versions and often used in genetic fingerprinting.
How to carry out genetic fingerprinting?
Dna is extracted and amplified via PCR
Restriction enzymes are used to cut dna near vntrs
Gel electrophoresis is used to seperate fragments by size
Radioactive probes used to visualise dna bands with trays or fluorescent probes used to visualise with uv light
Probability of match determined by computer analysis
What is PCR?
Amplifies dna
Happens in a thermocycler
Dna heated to above 90° to break hydrogen bonds between dna strands.
Cooled to 55° to allow primers to bind
Heated to 70° optimum temperature for taq polymerase, dna replication occurs
What is Gel electrophoresis?
Seperates dna rna or proteins based on size
Gel tray with solid agarose Gel placed into Gel tank
Wells close to cathode
Buffer solution poured over Gel until fully submerged, maintains constant pH
Voltage applied
Fragments of dna move towards anode due to dna negative charge
Smaller fragments mover further down Gel due to less resistance
Stain dna fragments and expose to uv radiation to visualise
What is Sanger sequencing?
Dna mixed with primers, dna polymerase, dna nucleotides and terminator bases
Dna heated to split strands and then amplified via pcr
Dna polymerase adds nucleotides to single stranded template
Terminator bases stops dna synthesis, strand is tagged with specific colour, corresponding to certain base
Dna fragments of all possible lengths produced.
Dna fragments seperated by length using gel electrophoresis.
Laser detects fluorescent colours in each fragments to determine sequence order.
Computer software analyses fragments to reconstruct original dna.
What are updated sequencing techniques used?
Shotgun sequencing,
massively parallel sequencing- allows sequencing simultaneously of millions of dna fragments
Exponentially increased speed and reduced cost
What is bioinformatics
Developing software, computing tools and mathematical models to create biological datasets as well as storing and analysing them. Includes nucleotides sequences of genes or even whole genomes.
What is computational biology?
Bioinformatoc tools and biological data to model biological systems and processes
What is genomics
The application of dna sequencing and computational biology to study genomes. Allows to identify patterns in our dna for disease risk. Also helps with epidemiology for potential outbreaks of disease and allows for vaccinations to be made effectively. Can detect antibiotics resistance and can monitor outbreaks.
What is dna barcoding?
Compares dna sequence of unidentified organism to database of standard baroda sequences for known species. Can identify common ancestors to build evolutionary trees with high degrees of accuracy.
It is fast and affordable. Classification of new species and updates classification, estimating evolutionary divergence based on predictable dna mutation rates
What is proteomics?
Examines complete set of proteins produced by the genomes. More proteins made than number of genes. This is explained by mrna splicing and post translational modification of proteins.
What is synthetic biology?
Design and construction of new biological parts, can be used to reengineer natural systems. Can create new genes to replace faulty ones. Can construct artificial genomes.
What is the process of making genetically modified organisms?
Desired gene is identified and isolated using restriction enzymes
Multiple copies of gene made using PCR
Vector gene cut using same restriction enzyme to create complimentary sticky ends.
Gene inserted into a vector along with marker gene
Vectors delivers gene into cells in different organism via electroporation
Cells with new gene identified with the marker gene (antibiotics resistance, gfp protein)
Cells with new gene are cloned
What is process of getting dna using rna sequence?
Mrna extracted from cells
Reverse transcriptase with dna nucleotides
Makes a dna strand identical to original dna strand.
The cdna strand formed, dna nucleotides and dna polymerase used now to regernate full dna molecules which codes for desired gene.
What are advantages of gmo
Plants
Less labour than pest/herbicides
Cheaper than pest/herbicides
Kills weed without harming crop
Increased yield
Better for environment
Pathogens
Potential treatment for currect incurable disease
Essential antibiotics created
Useful for vaccines
Creates dna libraries
Charming
Mass production of rare treatments
Drugs made more accessible
What are some disadvantages of gmo
Plants
Monocultures reduce biodiversity
Can cross breed to create resistant weeds
More vulnerable to changing climate
Other organisms harmed by toxin
Pests may evolve resistnace( selection pressure)
Pathogens
Accidental infection and disease outbreaks
Could revert back to harmful form
Biological warfare
Pharming
Animal welfare
Animals viewed as accomodites
What is pharming
Production of pharmaceutical and human medicines by inserting human genes into other animals. Can allow extraction of useful proteins from gm animals
What is genetic therapy
Replacement of faulty genes with healthy ones to treat or prevent genetic disorders
Somatic- replaces mutant alleles with healthy alleles in affected somatic cells. Can target specific cells in need of treatment. Not inheritable and only temporary.
Germ line- inserts healthy alleles into germ cells to prevent genetic disorders from birth. Influences all cells, cannot target specific cells. Is inheritable and permanent.
