| 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 |
