4.5 Application of reproduction and genetics Flashcards
What is genetic finger printing?
The unique set of bases in a persons genome
What was the goal of the Human Genome project?
To provide a complete accurate sequence of DNA base parings
identifying all genes and their location
What were the aims of the human genome project?
Understand diseases to improve treatment
Identify mutations
Risk assess treatments
Advance forensics
Research of evolution
What were the main findings of the Human genome project?
Fewer genes than predicted
More DNA repeats than expected
What is a stem cell?
An undifferentiated cell that can differentiate into different specialised cells
What are the types of stem cells?
Pluripotent
Totopotent
What are Pluripotent stem cells?
Adult cells that can differentiate into most types of cells
What are totopotent stem cells?
Embryonic cells that can differentiate into all types of cells
What are some ethical concerns with stem cells?
Embryos are alive
Possible unknown side effects
Expensive and unreliable
What technique did the Human Genome project use?
Sanger sequencing
What was the goal of the 100K Genome project?
To study genome variation in the UK
What technique did the 100k Genome project use?
Next generation sequencing (NGS)
What are the benefits of NGS over Sanger sequencing?
NGS is faster
NGS uses less resources- cheaper
Sanger can only process small samples
What other organisms have had their genome sequenced? Why?
Chimpanzees- Study evolutionary relationships and conservation
Mosquito- Study cause of insecticide resistance and to control population
Plasmodium sp- develop more effective drugs for malaria
What are the advantages of genetic sequencing?
Genetic screening for mutations
Early diagnosis
Embryonic screening for genetic conditions
Genetic counselling before conception
What are STRs?
Short tandem repeats
regions between intron and the number of times that region repeats
What is PCR used for?
Make copies of a DNA sequence
What are the steps in PCR?
- Heat DNA to 95* to separate stands
- Cool to 50-60* so primers bind to stands (annealing)
- Heat to 70* to allow DNA Polymerase to extend the sample
4.Cycle repeated
What is Gel electrophoresis used for?
The comparison of DNA samples
What are the steps to Gel Electrophoresis?
- DNA sample loaded into well at end of gel + Voltage is applied across the gel
- DNA attracted to +ve electrode due to phosphate groups negative charge
- Smaller fragments move more easily through gel pores so travel further
What are the applications of DNA fingerprinting?
Paternity testing
Forensics
classification
What are the pros of DNA fingerprinting?
Non invasive
Can us small samples
Exonerate false accusations
What are the cons of DNA fingerprinting?
Privacy violation
Storage issues
Mishandling of data could lead to wrongful convictions
What are the cons of DNA fingerprinting?
Privacy violation
Storage issues
Mishandling of data could lead to wrongful convictions
What is southern blotting?
A technique used to remove DNA fragments after electrophoresis
What are the steps of Southern blotting?
Nylon membrane placed in gel to ‘pick up’ fragments
DNA probes that are luminescent complementary bind to STR by bases
Film sensitive to x-rays from luminescent probes are placed on the film overnight
Film is exposed to autoradiographs
What is genetic engineering?
The transfer of a gene from one organism into the DNA of another
How is DNA cut directly out of the chain?
Restriction endonuclease hydrolyses phosphodiester links in the backbone
Cuts before and after the gene, removing it from the chromosome
What are the issues with cutting DNA directly?
Genome is massive and will cut many places
The base sequence must be known
Will contain non-coding introns that must be edited before contact with bacteria
What is the other enzyme that can be used to obtain a Gene sample?
Reverse transcriptase
How is reverse transcriptase used?
Reverse transcriptase can create cDNA from an mRNA strand of a desired cell
cDNA treated with DNA polymerase to make it double stranded
How is reverse transcriptase used?
Reverse transcriptase can create cDNA from an mRNA strand of a desired cell
cDNA treated with DNA polymerase to make it double stranded
What are the benefits of using reverse transcriptase?
mRNA is abundant in cells and is already spliced from its introns
How is recombinant DNA fromed?
Cutting the DNA leaves unpaired bases on the ends (sticky ends)
The same restriction endonuclease is used to cut plasmids
DNA ligase can join plasmids and DNA by thier sticky ends
How is the plasmid inserted into a host cell?
The vector (plasmid) is taken up in a solution by the bacteria
What are the concerns about genetic engineering using recombinant DNA?
Bacteria may pass on antibiotic resistant gene onto pathogenic bacteria
DNA fragments could transfer or activate Oncogenes
What is a GMO?
Genetically modified crops
genetically engineering crops for human consumption either to convey disease resistance or a desired characteristic
What are the advantages of GMOs?
Can help meet rising demand for food
Superior keeping qualities
What are the concerns regarding GMOs?
Cross pollination- large herbicide resistance
Damage biodiversity
risk to health as food
What is gene therapy?
inserting functional DNA sequences into cells to
counteract the effect of a defective gene
What is Germline Therepy?
Genes are replaced in germline cells so changes can be inherited
What is somatic cell therapy?
Alevites symptoms by replacing defective cells
these will wear and be replaced by defective cells however
What is Duchenne Muscular dystrophy?
A recessive sex linked disorder
The dystrophin gene is mutated and does not produce dystrophin causing muscle wastage
What drug is used to treat DMD?
Drisapersen
How does drisapersen work?
A sequence of bases complementary to the exon with the deletion mutation act as a patch
the molecular patch allows the exon to be skipped in translation and a more functional protein is formed
Where can stem cells be found?
Umbilical cord
Bone marrow
What are some uses of stem cells?
Tissue engineering
treatments for disease
study of growth
What is tissue engineering?
The study of the growth of new connective tissues or organs from cells and a collagenous scaffold
What is a scaffold in tissue engineering?
An artificial 3D printed structure to support the growth of new tissue
