M6 C21 Manipulating genomes

Question 1

what is a genome?

Answer 1

minimum genetic material that contains 1 copy of all genes of an individual

Question 2

what is gene technology?

Answer 2

the manipulation of an organisms dna to produce an organism or product

Question 3

what are autosomes?

Answer 3

chromosomes that aren’t sex chromosomes

Question 4

what is sanger sequencing?

Answer 4

stops dna synthesis due to modified nucleotides

Question 5

what are non coding regions of DNA called?

Answer 5

introns

Question 6

what are the 5 stops of producing a DNA profile?

Answer 6

extraction
digestion
seperation
hybridisation
development

Question 7

what happens in extraction?

Answer 7

DNA is extracted in PCR

Question 8

what does PCR stand for?

Answer 8

polymerase chain reaction

Question 9

what happens in step 1 of PCR?

Answer 9

excess nucleotide bases are put into the tube woth the DNA that we want to copy and primers. this is then heated up to denature the hydrogen bonds between bases to seperate the DNA

Question 10

What temperature is used in step 1 of PCR?

Answer 10

95 degrees

Question 11

what happens in step 2 of PCR?

Answer 11

annealing of the primers are added to each separate strand, they signal where the DNA should start and end replicating.

Question 12

what temperature is used in step 2 of PCR?

Answer 12

55-60 degrees

Question 13

what happens in step 3 of PCR?

Answer 13

the extension of DNA as 2 taq polymerase molecules attach to the 2 primers on the 2 DNA strands. they move along the new strand as free nucleotides bind to the complementary bases.

Question 14

what temperature is used in step 3 of PCR?

Answer 14

72-75 degrees as this is the optimum temperature of taq polymerase

Question 15

what happens after the extraction of DNA?

Answer 15

digestion

Question 16

what happens in digestion?

Answer 16

the strands of DNA are cut into small fragments by restriction enzymes at different points

Question 17

what happens in seperation?

Answer 17

the fragments are then separated by gel electrophorisis

Question 18

what happens in gel electrophoresis?

Answer 18

they seperate the fragments by legnth as the negative backbone is attracted to the positive elctrode at the end of the agar gel as an electric current is put through the gel

Question 19

what size fragments move quicker in gel electrophoresis?

Answer 19

smaller fragments

Question 20

what happens in hybridization?

Answer 20

radioactive or fluorescent DNA probes are added in excess to the fragments. they bind to the DNA strands separated in the gel and the excess is washed off

Question 21

what happens after hybridization?

Answer 21

development of the evidence as the membrane with the dna evidence is put onto a x-ray film which reveals the dark bands where the dna is/ where probes have attached

Question 22

what can DNA profiling be used for?

Answer 22

crime scene analysis
paternity tests
immigration relationships
see how at risk someone is for a particular disease

Question 23

what is sanger sequencing?

Answer 23

radioactive labelling of bases

Question 24

what is added in sanger sequencing?

Answer 24

DNA for sequencing is mixed with a primer, DNA polymerase, excess free nucleotides, terminator nucleotides

Question 25

what happens in sanger sequencing?

Answer 25

heated at 96 degress to seperate the strands cooled to 50 degrees to anneal the primers heated agasin to 60 degrees so polymerase can create new strand by adding complementary bases

Question 26

what happens when a terminator base is added instead of a 'normal' base?

Answer 26

the synthesis of dna is terminated as no more nucleotides can join as there is a lower amnount of terminators compared to the nucleotides lots of different lenghts of fragments are produced.

Question 27

what happens after many cycles of Sanger sequencing?

Answer 27

all the possible dna chains will have been produced. they are then seperated by length in capillary sequencing which works like gel lectrophoresis

Question 28

what detects the final base on each fragment of DNA?

Answer 28

fluorescent markers on the terminator bases at the end of each sequence

Question 29

how are the final bases recognized when sequencing DNA?

Answer 29

Lasers detect the different bases as they all have different fluorescent colors for each 4 bases this is then fed into a computer to sequence a genome

Question 30

what can we use dna sequencing for?

Answer 30

bioinformatics- model biological systems, genes linked to certain diseases sequencing the genome identifying species analyse pathogen genomes look at eveloutionary relationships

Question 31

what is synthetic biology?

Answer 31

genetic engineering use biological systems in industrial context- drug production synthesis of new genes to replace faulty make a new organism

Question 32

what are the principles of genetic engineering?

Answer 32

-genetically modifying dna from different organisms to produce recombinant dna -genes are isolated from 1 organism and inserted into a other organism using a vector

Question 33

what are the 1 way of isolating a gene in genetic engineering?

Answer 33

1- mrna extracted from cells to show what gene is being expressed. reverse transcriptase copies mrna back to cdna

Question 34

how can a gene be isolated by restriction endonuclease in genetic engineering?

Answer 34

the restriction endonuclease cuts gene from the dna leaving sticky ends

Question 35

what vectors are commonly used in genetic engineering?

Answer 35

bacterial plasmids

Question 36

how is the gene inseretd into0 the plasmid/

Answer 36

restriction endonucleases cut open the plamsid leaving it with complementary sticky ends to the ends of the dna frament being inserted

Question 37

what does dna ligase do?

Answer 37

forms phosphodiester bonds between the sugar and phosphate groups on 2 strands of dna joining them together

Question 38

what does the plamsid do once inside a host cell?

Answer 38

combines with the host cells dna to form recombinant dna

Question 39

how does the vector get into the host cell|?

Answer 39

place bacteria and plamsids in ca rich solution heated so bacterial mebrane is more permeable and plasmids can enter

Question 40

how does electroporation get the vectors into the cell?

Answer 40

small electrial current is applied to bacteria makes membrane more permeable so plasmids can move in

Question 41

what is electrofusion and how is it used?

Answer 41

tiny electric currents are applied to 2 different cells this then fuses the cell and nuclear membranes of the 2 cells so their dna becomes mixed used in GM plants

Question 42

what are reasons for genetically modified organisms?

Answer 42

increased growth grows transplant tissue resistance to pests grwoth in harsh cinditions better food security medical benefits

Question 43

what are some reasons against GMO'S?

Answer 43

losses for small farmers playing god exposure to allergens health risks resistant bacteria developing in humans viability of offspring of GMO's toxic compounds in environment tested on animals