manipulating genomes

Question 1

the genome

Answer 1

all the genetic material an organism contains . 2 percent exons, large non coding reigons (introns) removed from mrna before translation into polypeptide chains

Question 2

minisatelite vs microsatellite

Answer 2

miisatelite- 20-50 base pairs repeated 100 times

microsatellite- 2-4 bases repeated 5-15 times

identical twins = identical satellite pattern

Question 3

electrophesis extra points

Answer 3

dna attaches to the anode due to negatively charged phosphate groups, when smallest fragments reach the end, the electric current is switched off

gel placed in alkaline buffer solution - denatures dna fragements to expose the bases

southern blottoing technique used, strands transferred into nitrocellulose paper/ nylon membrane placed over gel - membrane covered w sheets of dry absorbent paper to draw alkaline solution containing dna through membrane by capillary action .

Question 4

the process of DNA sequencing

Answer 4

1. dna sequencing mixed with primer, polymerase and terminator bases
2. mixture placed in thermal cycler- goes through speerating strands and annealing primers by sswithcing from 96 to 50 degrees @ repeated cycles
3. 60 degrees, dna poylymerase builds new strands by adding nucleotides to single strand dna
4. every time terminator base incoroporated ( terminator bases were added in lower amounts) , results in dna framgents of diff lengths depending on where in chain it got incorporated.
5. eventually, all possible dna chains will be produced w reaction being stopped at every base
6. dna fragment seperated by length according to capillary sequencing, woks like gel electrophesis
7. flourescent markers identify final base of each fragment and laers detect diff colours and order of sequence
8. order of bases in capillary tuebs show seq of new, complementary strand of dna which is made. used to build up sequence of original dna strand
9. data from sequencing process fed int ocomputer to assemble genome . scientists use it to find bits that code for specific characteristics linked to diseases etc..

Question 5

uses of dna profiling

Answer 5

performed on traces of dna left at scrime scene

assists in identification of individuals or familial relationships

. identifying ppl at risk of developing diseases

.allows for risk asessments

Question 6

dna sequencing

Answer 6

first: sanger developed technqiues for sequencing nucleic acids from viruses and then bacteria- involved radioactive labelling of bases and gel electrophesis (flourescent tags use as ALTERNATIVE!)

Question 7

hgp

Answer 7

scientists all over the world worked together to map genome .

developing tech and faster sequencing techniques= allowed for faster mapping of human genome

Question 8

next gen sequencing

Answer 8

high throughput sequencing

.eg sequencing reaction takes place of plastic slide (flow cell) instead of gel . allows large clusters to be sequenced and imaged at the same time (with terminator bases ) - “massively paralell sequencing “

.reduced costs, and more efficient ( Sequencing is much faster)

Question 9

bio informatics etc..

Answer 9

computers than help anayse raw biologica data eg development of algorithms, mathematical models etc ( makes sense of enormous data )

. important in working out 3d structures of proteins and understanding gene regulation - tldr helps use info from dna sequencing eg identifying genes linked to diseases

Question 10

genomics

Answer 10

analysing structure and function of genomes

.realisation that genes worked with environment to affect physiology and likelihood of disease development

Question 11

sequencing pathogen genomes allows doctors and scientists to….

Answer 11

find source of infection

.identify antibiotic resistant bacteria so antibiotics used
only when effective+ tracking trnasmissions of TB so it can be treated as it spreads quickly around the world

.scientists: track outbreak of dsiease

.scientsits: identify reigons of pathogen genome to develop new drugs

Question 12

dna barcoding ( an example of genome sequencing )

Answer 12

identifies sections of genomes that are common to all species but vary between them.

ibol- identfiying species using short sections of dna from genome- chosen section is 648 base pair of cytochrome c oxidase - small enough to be sequenced quickly + cheaply and varies anough to give clear differences

. suitable reigons for barcoding in fungi and bacteria nto identified yet so yo ucant barcode them

Question 13

use of genome seqwuencing

Answer 13

evolutionary relatin ship- calculating basic mutation rate of dna allows to calculate how long ago sepcies diversion occured from common ancestor

Question 14

genomics and proteomics

Answer 14

proteomics, study of amino acid sequences

. dna sequence allows prediction of sequence of amino acids in proteins produced . some genes code for many proteins

Question 15

spliceosomes

Answer 15

exons that are removed adn to be translated from dna during transcirption joined together by enzyme complexes (Specilosomes) to give mature functional mrna thus one gene= produce any versions of functional mrna- thus code for diff amino aicds= thus phenotypes

Question 16

protein modifiation

Answer 16

some proteins modified - shortened or lengthened to give variety - proteonomics give increasing knowledge of relationship between genotype and phenotype

Question 17

synthetic biology technqiues

Answer 17

genetic engineering- genetic modifcation of an organism

.using biological systems in industry - eg enzymes and production of drugs from micro organsims

.synthesis of new genes- replace faulty genes- cystic fibrosis

.syntehsis of entire new oganisms

Question 18

green box: dna sequencing and clinical intervention

Answer 18

mrsa was linked to one hospital worker after dna sequencing thus preventing spread and deaths

Question 19

genetic engineering

Answer 19

isolting gene and transferring using vector

.restriction endonculeases unevely cut the dna strands - unpaired exposed bases= sticky ends= easier to insert gene

.another technique- reverse transcirptase on mrna to produce complementary dna - easier to idnetify desired gene

Question 20

formation of recombinant dna: making hte vector

Answer 20

bacterial plasmid- has marker gene ( eg antiiotic resistance) - enable to determine that hte bacteria has taken up plasmid by growing bacteria in antibiotic

. insert dna fragment into plasmid by cutting open using same reaction endonuclease to isolate dna fragment - causes complementeary sticky ends which are now joined by dna ligase

.plasmids given second marker gene-> show plasmid contaisn recombinant gene

.plasmid tehn cut4 by restriction enzyme within marker gene to insert desired gene .

(marker genes now= floruescene not antibotic )

Question 21

transferring vector t

Answer 21

process= transformation

methods=, culture bacterial cells in calcium solution and increase temperature. ( makes membrane porous)

electroporation (current makes membranes porous) ( electric urrent has to be carfeully monitored so not to destroy the memebrane

Question 22

electrofusion (Another way of transferring vector)

Answer 22

currents applied to memb of 2 differetn cells = fuses cell and nuclear memb of both cells to make hybrid cell. used to produce GM plants

used to make monoclonal antibody - (antibody combiens with tumor to divide rapidly)

Question 23

engineering plants

Answer 23

use agrobacterium tumefaciens - causes tumours in plants. combine desired gene ( eg pesticide protection ) with the bacteria with flourescent amrker gene and carry int plant cell dna. callus is formed (mass of gm plant cells to be grown into plant )

.electrofusion- another method of making transgenic plants- remove cellulases form cell walls and electrofuse them to form polyploid cell. plant hormones stimulate growth of cell wall followed by callus fomration and production of cloned transgenic palnts

Question 24

engineering animals

Answer 24

membranes harder to manipulate - harder to engineer dna .

animals produce preteins which can be used to cure CF + huntingtons etc

Question 25

advantages of genetic manipulation

Answer 25

.bactria used to produce insulin + vaccine

.gm microogranisms- store record of dna of another organisms (eg in bacteria) - useful for dna sequencing projects

gm microorganisms used for development of medicine and gene tech (Eg epidemic research ). cons: suspicion of bio warfare using genetically modified pathogens (eg resistance)

Question 26

gm soya beans have..

Answer 26

insect resistance - produces bt proetin toxic to insects

.resistance to weed killer- allows for higher crop yield

Question 27

pros/ cons of pest resistance

Answer 27

.reduce amount of pesticied= decrease cost. increase yield

non pest and insect eating preds can be damaged by toxins in gm plants

.pests develop resistance

Question 28

pros/ cons of disease restance?

Answer 28

.increases crop yield

.transferred genes might spread to wild popualation + cause problems

Question 29

pros/ cins of herbidcide resistance

Answer 29

reduces competing weeds = inc yield

reduced biodiversity due to overused herbicides

Question 30

pros / cons of extended shelf life

Answer 30

reduces food waste

reduces commericla value and demand

Question 31

pros / cons of growing conditions

Answer 31

grow in wider range of conditons and survive droughts

NO CONS

Question 32

pros. cons of nutritional valuee

Answer 32

enhanced level of vitammins

allergic reaactons to proteins made in gm corps

Question 33

pros/ cons of medical uses

Answer 33

used for human medicines/ vaccines

NO CONS

Question 34

Patenting problems

Answer 34

poor countries cant use gm crops because they are patented ( eg soya was apptented so that farmers could only buy them and grow them to use or sell them or porcess them onlt in the year bought , cnat save the seed to grow next year )

.pros L IRI engineered flood resistant rice to support farmers

Question 35

gm animals

Answer 35

swine fever resisetant pigs

faster growing salmon ( producees growht hormones all year and grows to full adult size in half the tike )

Question 36

pharming

Answer 36

. production o human medicines from animals

.creating animal models- developing dieasing in animals for development of new therapies. eg mice hace genes deleted so they develop cancer

.creating human proteins - human gene introduced into cow or sheep egg with promoter sequence so gene only expressed in mammary glands. ftransgenic female embryo returned to mother and whne it matures and gives brith it will produce milt that contains desired human protein to be harvested

Question 37

ethical issues

Answer 37

should animals act as models to human diseasE

is it right to put human genes itno animals??

is it right to put genes from other species into animals wihtout being ertain that it wont harm ?

.does genetically modifying animals reduce them to commodities?

is welfare compromised?

Question 38

somatic and germ line therapy

Answer 38

used to treat faulty genes that cause CF, haemophilia and severe combinedi mmunodefficiency (SCIDS)