C2 use of polymorphisms in mapping

Question 1

what is linkage a measure of

Answer 1

how far apart genes are from each other

Question 2

what is linkage

Answer 2

how likely a meiotic recombination event is between 2 loci

Question 3

what did RFLPs, DNA seq, gel electrophoresis/southern blotting, PCR allow

Answer 3

polymorphisms without corresponding traits/phenotypes to be used as genetic markers

Question 4

are the alleles of 2 microsatellite loci always inherited together, mostly together, or 50/50 chance
what does this indicate

Answer 4

complete linkage
partial linkage
no linkage

Question 5

what is partial linkage

Answer 5

meiotic recombination (croos-over) between M1 and M2
frequency of recombinants proportional to physical distance apart

Question 5

what is partial linkage

Answer 5

meiotic recombination (cross-over) between M1 and M2
frequency of recombinants proportional to physical distance apart

Question 6

what is no linkage (unlinked)

Answer 6

independently segregating, inheritance of one allele at one locus has no influence on an allele at other locus

Question 7

in terms of linkage what does phase mean

Answer 7

on the same chr

Question 8

in terms of linkage what does haplotype mean

Answer 8

order of in-phase alleles along chr

Question 9

what are linkage maps based on

Answer 9

frequency of marker separation during meiosis through generations

Question 10

what is the engine of the linkage map study

Answer 10

meiotic recombination

Question 11

units of linkage measurement

Answer 11

human genome - cM (centimorgan)
1cM= recombination fraction of 1/100 meioses
(physcially eqvn to between 0.7 and 1 Mb of DNA)

Question 12

what human disorders were located by linkage

Answer 12

cystic fibrosis
huntingtons
breast cancer

Question 13

genetic map problems for disease gene identification and human genome seq

Answer 13

-genetic mapping is a mathematical exercise
-only provides a rough idea of where markers are and where disease gene is located

Question 14

how do you collate, organise and distribute huge quantities of DNA to make a physical map

Answer 14

-a library
(storage/duplication/distribution)
-a database
(relationships)

Question 15

why do we need to clone DNA into genomic libraries

Answer 15

a whole genome is too big and complex- limited in quantity
libraries offer infinite ‘photocopies’ (clones) of any bit of the genome

Question 16

how is DNA cloned into library

Answer 16

DNA strands chopped up and stored to make a genomic DNA library

Question 17

what do natural bacteria sometimes carry on plasmids/episomes

Answer 17

genetic material

Question 18

molecular biologists can engineer the plasmids to do what

Answer 18

carry bits of foreign DNA of interest

Question 19

what happens to the engineered bacteria and why do scientists need them

Answer 19

bacteria become photocopies; producing infinite quantities of identical (cloned) copies of that DNA
needed for analysis

Question 20

what is the restriction enzyme used to cut DNA at specific seq in genetic engineering

Answer 20

EcoRI

Question 21

in genetic engineering what is the specific sequence that DNA is cut at

Answer 21

GAATTC

Question 22

after DNA is cut in genetic engineering what happens

Answer 22

the cut ends have overhangs which allows them to reform in the presence of ligase

Question 23

5 stages of making a DNA clone library summary

Answer 23

1. human genomic DNA broken down
2. fragments placed in vector
3. stored in bacteria or yeast as a clone library (BACs, YACs)
4. single bacterium with one BAC in it will grow into a clonal pop/colony
5. (libraries can be made from mRNA in tissue, convert to cDNA)

Question 24

what is used as probes for FISH and what does it tell is

Answer 24

BAC/YAC clones
where they are located on which chr

Question 25

what is the term given to clones that overlap

Answer 25

chr walking

Question 26

what is a contig

Answer 26

a virtual stretch of genomic DNA made up from the analysis of multiple overlapping DNA clones
contiguous

Question 27

eventually the complete genome can be reconstructed in what

Answer 27

clones

Question 28

now have access to the precise chromosomal DNA that…

Answer 28

-contains a gene associated with a particular genetic disorder
-is a convenient unit of the human genome that can be sequenced