Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: 21.4 Locating genes, genetic screening, and counselling

Questions and Answers List

level questions: 21.4 Locating genes, genetic screening, and counselling

QuestionAnswer
DNA profiling uses- Paternity tests - Forensics scientists can identify criminals - Genetic profiling to predict diseases - Animal breeding
Minisatellite- VNRT - Variable no. tandem repeats
VNTR- A core sequence that is found between genes, these may repeat themselves up to 100 times - The no. of repeats varies from person to person, even though the genes are the same - If there is a mutation in the VNTR it will not be expressed in the phenotype as it is in the DNA but not the gene
VNTR fact- The chance of 2 people having the same minisatellite about 30:1 so can be used for DNA profiling
Making a genetic profile/fingerprinting- Extraction - Digestion - Separation - Hybridisation - Development
Genetic screening process (1)- Remove cells e.g. from cheek (from adult or embryo) - Extract DNA - Digested DNA using restriction enzyme
Genetic screening process (2)- Amplify DNA using PCR - Separate DNA using electrophoresis - The DNA is negatively charged so it move towards + electrode - Smaller frags move quicker than larger frags - This means that frags seperate into bands - Denature using an alkali
Genetic screening process (3)- Add radioactive/fluorescent gene probe - Use X-ray (film)/UV to identify gene
How do you find genes?- DNA gene/allele probes - Which is a short single stranded piece of DNA, bases complementary to the DNA in a certain gene - Can be fluorescent or radioactively labelled
FOR genetic screening- Identify tumor suppressor mutations - Identify genetic conditions of embryo/fetus - Identify carrier of recessive conditions
AGAINST genetic screening- Could lead to anxiety - Could lead to eugenics - May lead to termination
Genetic Counselling- The counselling of patients/parents to establish the risks of a genetic disease/producing a child with a genetic disease
Personalised Medicine – a growing field- People with different genotypes respond differently to the same drug - Personalised medicine could save NHS money from wasted prescriptions
Genome- All the genes of an organism
Proteome- Entire set of proteins expressed by a genome, cell or organism at a certain time
Why would an artificial gene be differnet to a normal gene?- No introns
How could the gene be cloned?- PCR (in vitro) - GM (in vivo)
Why is it easier to sequence a bacterial genome rather than a eukaryotic genome?- Bacterial DNA is shorter - Bacterial DNA has no histones - Bacterial DNA has no introns
What is the importance of sequencing bacterial genome?- Enables to produce new vaccines + antibiotics - identify treatments - Sequence it frequently as they mutate - work out rate at which they are evolving
Why may knowledge of bacterial proteome be useful?- Shows what proteins (antigens) you can target in the bacteria