Application Of Reproduction And Genetics Flashcards
Define stem cells
Undifferentiated cells that can be differentiated into different specialised cells
What is tissue engineering ?
The cultivation of cells on a framework of synthetic material to from tissue that can be used to repair tissue or organs
What are the 2 types of stem cells?
Pleuripotent cells - Adult cells that can differentiate into most types of cells
Totipotent Cells - Embryonic cels that can differentiate into all types of cells
What are the associated issues with using embryonic cells?
- Destruction of potential life
- Expensive and unreliable technology
- Possible long term and unknown side effects
Define genomics
The study of structure, function, evolution and mapping of genomes. It could to be used to personalise healthcare
Explain what the Human Genome Project is
The original project to sequence the whole human genome. Its purpose was to improve knowledge and understanding of genetic disorders and improve their diagnosis and treatment.
It used Sanger Sequencing - this sequences small sections of DNA and it takes a long time
Explain what the 100k Genome Project is
A project to study the genomes of 100,000 people in order to study genome variation in the UK.
Uses Next Generation Sequencing which is much faster then Sanger - the sequencing of a whole genome can be done in a few hours
What are the advantages of genetic technology ?
- Ability to scan patients DNA sample for mutated sequences and compare against normal version
- May be possible to routinely screen for adult onset disorders (Alzheimer’s )
- Screen embryos to detect any presence of disorders.
- Use of genetic screening and the value of genetic counselling to give potential parents the options
Disadvantages of genetic technology
Ethical issues such as :
- Ownership of genetic information
- Potential Discrimination
- Misuse of data
- Screening embryos has led to concerns over choosing alleles to ensure specific characteristics e.g. designer babies
- Increase abortion rates
Why have genome projects sequenced primates genomes?
Look at evolutionary relationship and to conserve the species e.g. chimpanzees
Sequencing of the Anopheles gambiae mosquito
- This is a vector for the malarial parasite
- By sequencing the genome it allows scientists to study the cause of insecticide resistance and develop new chemicals to reduce the population
What are the uses of DNA profiling and PCR ?
- Paternity tests
- Identification of siblings and checking between identical and non identical twins at birth
- Identification of relatives for immigration purposes
- Forensically ruling out or incriminating suspects
- To identify closely related organisms for classification purposes
Advantages and Disadvantages of DNA profiling
+ Non-invasive
+ Can use on really small samples
+ Can exonerate the falsely accused
- Privacy and civil liberties issues of taking DNA
- Safe storage issues
- Mishandling of DNA evidence may lead to wrongful convictions
Explain the steps of electrophoresis
1) DNA samples are loaded into wells at one end of the gel and a voltage is applied across the gel
2) DNA is attracted to the positive electrode due to its negative charge on the phosphate group
3) Smaller fragments find it easer to migrate through pores in the gel and so travel further than large fragments in the same time
4) Fragment size can be estimated by running DNA ladder ( which contains fragments of known size ) alongside.
What is PCR
Polymerase chain reaction
- used to amplify small sections of DNA rapidly
Amplifies the STRs by using a primer (single stranded DNA) which is complimentary to the start of the sequence
Describe the process of PCR
- Heat the DNA to 95 degrees to separate 2 strands
- Cool to 50-60 degrees to allow the primers to bind to the DNA strands (annealing)
- Heat to 70 degrees allows a thermally stable DNA polymerase to add complimentary nucleotides by forming the phosphodiester bonds in the sugar- phosphate backbone
- Cycle is repeated, after 40 cycles over a billion copies of the target sequence can be produced from just one piece of DNA
DNA Profiling
Can be read as bands of DNA on a agarose gel.
It is used to compare the DNA from one organism to another
It’s done by comparing sections of the DNA called STRs, introns that are highly variable.
To compare DNA, it is necessary to make copies in a process called PCR and then compare the by using Gel electrophoresis .
