Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
14 Cards in this Set
- Front
- Back
|
why doesn't all of an organisms genome (all the genetic material in an organism) code for proteins |
because some of the genome consists of repetitive, non coding base sequences - bases sequences which don't code for proteins and repeat over and over. |
|
|
what is genetic finger printing |
comparing in individuals the number of times a sequence of nucleotides is repeated at different places in the genome |
|
|
why are two people unlikely to have the same genetic fingerprint |
1) the number of times these sequences are repeated differs from person to person = so the length of these sequences differs too 2) the repeated sequence occurs in lots of places in the genome so will be different for each person 3) the chance of 2 individual having the same number of sequence repeats at each place theyre found in the DNA is very low. |
|
|
what are the first steps of making a genetic finger print (before electrophoresis) |
A sample of DNA is obtained from a persons blood - PCR is used to make lots of copies of the areas of DNA that contain the repeated sequence - primers are used that bind to either side of these repeats and so the whole repeat is amplified - a fluroscent tag is added to all the DNA fragments so they could be viewed under UV light. |
|
|
what happens to the DNA fragments when they unergo electrophoresis |
the DNA mixture is placed into a well in a slab of gel and covered in a buffer solution that conducts electricity - an electric current is passed through the gel - DNA fragments are negatively charged so they move towards the positive electrode at the far end of the gel. - small DNA fragments move faster and travel further through the gel so the DNA fragments seperate according to size the DNA fragments are viewed as bands under UV light = genetic finger print |
|
|
how can two genetic fingerprints be compared |
if both finger prints have a band in the same location on the gel - it means they have the same number of nucleotides and so have the same number of sequence repeats = its a match |
|
|
how is genetic finger printing used in determining genetic relationships |
we inherit the repetitive non coding base sequences from our parents. - this means the more bands on a genetic finger print that match the more closely related (genetically similar) two people are. - if lots of bands on the fingerprint match, then that person is probably related - the higher the number of places in the genome compared, the more accurate the test result
|
|
|
how is genetic fingerprinting used to determine genetic variabilitiy within a population |
the greater the number of bands that don't match when comparing two pieces of DNA the more genetically different two people are. this means you can compare the number of repeats at several places in the genome for a population to find out how genetically varied that population is |
|
|
describe the procedure used with genetic finger printing in forensic science |
the DNA is isoated from all the collected samples (crime scene and suspects) each sample is replicated using PCR - the PCR products are run on electrophoresis gel and the genetic finger prints produced are compared to see if any match |
|
|
when is genetic finger printing useful in medical diagnosis |
it can be useful when diagnosing genetic disorders and cancer -its useful when the specific mutation isnt known - useful when several mutations could have caused the disorder because it identifies a broader altered genetic pattern |
|
|
how can genetic finger printing be used to screen embryos for genetic disease |
PGH screens embryos created by IVF for genetic disorder before theyre implanted into the uterus. the faulty regions of the parents DNA are used to produce genetic fingerprints, which are compared to the genetic finger print of the embryo. if the finger prints match the embryo has inherited the disease. it can be used to screen for cystic fibrosis, huntingtons disease |
|
|
how can genetic finger printing be used to diagnose sarcosmas |
the genetic fingerprint of a sarcoma can be compared to to the genetic finger print of a patients tumour - if there's a a match the sarcoma can be specifically diagnosed and treatment can be targeted to that specific type. |
|
|
how can genetic finger printing be used on animals and plants to prevent inbreeding |
genetic finger prints can be used to identify how closely related individuals are - the more closely related individuals are the more similar their genetic finger print will be. |
|
|
what are the problems with inbreeding |
it causes health, productivity and reproductive problems inbreeding decreases the gene pool (the number of different alleles in a population) = lead to an increased risk of genetic disorders = leading to health problems |
