A2C2 - Chapter 11 - Application of Reproduction and Genetics Flashcards
(50 cards)
What is the human genome project?
A group of scientists used sanger sequencing to successfully map the entire human genome.
What is DNA sequencing?
Identifying the base sequence of a DNA fragment.
What is sanger sequencing?
A method of DNA sequening in which requires relatively short sections of DNA at a time.
It takes ages tho.
Outline the potential benefits of the Human Genome Project.
Allows for development of targeted medicine with greater accuracy of diagnosis.
Early detection of disease.
Enables the study of whether mutation has occured of different genes.
What is the 100K genome project?
UK Govt project that aims to study variation in the human genome amongst 100,000 UK citizens.
This uses Next Generation Sequencers (NGS)
Describe next generation sequencing (ngs)
A faster, cheaper method of dna sequencing that only takes a few hours to map out an entire human genome.
Describe genetic counselling.
Service aiming to provide information and advice to those affected by or at risk of genetic disease.
Helps affected individuals or familes to make an informed decision.
What is genetic screening?
Testing individuals for faulty genes.
Used to detect disorders such as cystic fibrosis, huntington’s disease and haemophillia.
Outline potential disadvantages to genetic screening.
Screening for issues like cancer only shows an increased risk therefore can cause unneccesary stress and anxiety.
Risk of false positives or negatives.
Misuse of information/what if people like health insurance discriminates?
Who should actually be screened?
Give some examples of organisms other than humans which have been genetically screened.
Chimpanzees and other primates
Anopheles Gambiae (mosquito)
Plasomodium Parasite
How has sequencing Anopheles Gambiae been useful to humans?
The anopheles was able to have insecticide resistance
Hence, with the sequencing humans were able to produce insecticide that anopheles are susceptible to.
Outline the advantage of sequencing the genome of Plasmodium sp. to humans.
Plasmodium has developed drug resistance.
Enables drugs that are being developed to be more effective.
What is genetic fingerprinting?
A technique used to genetically identify an organism
Used in forensics, screening for hereditary disease, paternity testing, selection for clinical trials.
What are exons?
Region of DNA coding for amino acid sequence.
What are introns?
Non-coding regions of DNA.
What are STRs?
Short tandem repeats
Sections of repeated nucleotides in introns that produces variation in individuals.
What techniques can be used to produce a genetic fingerprint?
PCR
Gel electrophoresis
What is PCR?
Polymerase Chain Reaction
Used to amplify fragments of DNA.
Describe the reaction mixture in the first stage of PCR. (4)
Contains fragment to be amplified.
Primers that are complimentary to the start of the fragment.
Free nucleotides to match up to exposed bases.
Taq polymerase to create the new DNA.
What is Taq polymerase?
A thermally stable enzyme that synthesises a double stranded molecule of DNA from a single strand template strand using complimentary nucleotides.
Summarise the process of amplifying DNA fragments in PCR.
Heated (90C) to break hydrogen bonds between DNA strands.
Cooled (55C) to allow primers to bind (annealing)
Heated (70C) to activate Taq Polymerase and allow free nucleotides to join.
New DNA acts as a template for the next cycle.
What is gel electrophoresis?
A technique that separates nucleic acid fragments or proteins by size via electric current.
How does gel electrophoresis work?
DNA fragments of varying lengths are placed into one end agarose gel.
Electric current is applied. DNA fragments move towards the positive end of the gel.
Shorter fragments travel further. The pattern of bands created is unique to every individual.
What is genetic engineering?
Modification of a genome of an organism by the insertion of a desired gene from another organism.
This enables the creation of organisms with desirable characteristics.