gene technology Flashcards

Question

how does gene therapy work to change the mutated gene?

Answer 1

if the mutated alleles are: 2 recessive - add dominant to supplement them 1 dominant - silence it (add DNA to middle of allele so it doesn't work anymore)

Answer 2

somatic - altering alles in body cells particularly those affected by disease - eg epithelial cells in lungs for cystic fibrosis (doesn't affect sex cells, could be inherited) germ line - altering alleles in sex cells disease can't be inherited as every sex cell has been altered

Answer 3

working allele inserted into cells using vectors vectors include: - altered viruses - plasmids - liposomes (spheres of lipids)

Answer 4

short strands of DNA have a specific base sequence complementary to the target allele means they will bind (hybridise) to the target allele if present has a label attached so it can be detected - fluorescence (use UV light) - radioactive (use x ray film)

Answer 5

DNA fragment obtained (restriction endonucleases and separated using electrophoresis) - transferred onto a nylon membrane sample of DNA incubated with DNA probe (with label) if target allele present, DNA probe will bind to it - probe not removed when washed use UV light or x-ray film to detect DNA probe, if present DNA in sample must be single stranded to allow the probe to bind

Answer 6

locating specific alleles of genes see if persons DNA contains mutated alleles that causes genetic disorders used for screening

Answer 7

1. identify heritable conditions screened to identify mutated allele - means treatment can be started earlier eg in cystic fibrosis 2. determine how patients will respond to drugs screening for a specific mutated allele can show if someone has it so if a specific drugs will work 3. identify health risks inheriting a particular mutated allele can increase risk of developing certain cancers - allow them to make life choices to reduce their risk however could lead to discrimination by insurance companies or employers if some people have a higher risk of disease

Answer 8

locate specific alleles can screen for: - heritable conditions - responses to drugs - health risks

Answer 9

advising patients and families about the risk of genetic disorders advise on screening and the results - the risks of it being passed on to offspring - advice on future steps eg most effective prevention or treatments - explain potential consequences of disease eg economically screening can help identify if someone is a carrier of a mutated allele and what type (showing what genetic disorder it causes)

Answer 10

medicines that are tailored to an individuals DNA genes mean different people respond to drugs in different ways - makes them more effective for some than others can be used in prevention if mutated allele detected if doctors have genetic information it can be used to predict responses to drugs therefore prescribe the most effective

Answer 11

can identify people with allele who are at risk of developing specific diseases - can make lifestyle choices to reduce their risk eg diet can help potential parents chose to have children or not - may not want to risk passing on harmful alleles

Answer 12

designer babies - unethical could lead to discrimination in workplaces or for insurance - for people who have a higher risk of developing certain diseases

Answer 13

genome contains variable number tandem repeats - base sequences that don't code for proteins and repeat next to each other number of times the sequences are repeated = length in nucleotides - this varies between people repeats also occur at different places in the genome - varies between people probability of 2 people having same genetic fingerprint is very low - need same number of VNTRs at same place in genome

Answer 14

restriction endonucleases used to at specific base sequences to cut VNTRs out results in fragments of varying lengths - depending on number of repeats apified using PCR = many copies

Answer 15

DNA contains a phosphate group = negative so attracted to positive electrode at end of gel

Answer 16

sample of DNA obtained (blood, saliva etc) PCR used to make copies of area of DNA fragment containing VNTRs electrophoresis used to separate them fluorescent tag added - visible in UV 1. DNA mixture placed in well in gel covered in a buffer solution that conducts electricity 2. electric current passed through gel DNA fragments negatively charged move towards positive electrode at far end of gel 3. small DNA fragments move faster so travel further larger ones don't travel as far - DNA fragments separate according to size viewed as bands under UV light (fragments had fluorescent tag)

Answer 17

Fragments transferred from gel to nylon membrane Membrane incubated with fluorescently labelled DNA probe Viewed as bands under UV light

Answer 18

method used to determine an organisms genetic identity done by electrophoresis depends on number of VNTRs in the organisms DNA - shown as bands under UV or radioactive light

Answer 19

multiple fingerprints can be compared remember fragments separate based on length (in nucleotides) and therefore VNTRs shorter move further if both fingerprints have a band at the same location, they have the same number of nucleotides (so same number of VNTRs) they match

Answer 20

compare samples of DNA collected from crime scenes to samples from suspects 1. DNA isolated from crime scene and suspects 2. each sample replicated using PCR 3. samples run on electrophoresis gel to produce genetic fingerprints 4. compared to find a match - if samples match, it can link a suspect to a crime scene

Answer 21

genetic fingerprint refers to a unique pattern of alleles can be used to diagnose genetic disorders and cancer useful when specific mutation isn't known or when caused by multiple mutations because it identifies a broader genetic pattern

Answer 22

used to prevent interbreeding - decreases gene pool - increased risk of genetic disorders - heath and productivity issues used to identify how closely related two individuals are so they won't be bred together (less related bred) more similar fingerprints means more closely related

Answer 23

VNTR sequences inherited from parents - roughly half from each parent more bands that match = more closely related eg paternity tests - more matches = more likely to be father

Answer 24

the more bands that don't match = less related (more genetically different) can find out how genetically varied a population is the more the number of repeats varies at different places = more genetic variability

Answer 25

- determining genetic relationships - determining genetic variability - forensic science - medical diagnosis - plant and animal breeding

Answer 26

short sections of single stranded DNA base sequence is complementary to DNA fragment so it binds allows polymerase to bind and produce the new fragments

Answer 27

mRNA and bacterial have introns removed means bacterial DNA easier to study fewer non-coding regions (introns) so knowledge of genome more easily related to proteome - less non-coding to get in the way

Answer 28

tells RNA polymers where to start transcription of DNA means gene transcribed

gene technology Flashcards

(52 cards)