Manipulating genomes

Question 1

DNA profiling

Answer 1

• PCR
• electrophoresis
• fluorescent tags

Question 2

PCR

Answer 2

• at 95 degrees DNA fragment splits into 2 strands due to the complementary hydrogen bonds between baes
• temperature is then reduced to 55 degrees and primers anneal to the strands
• then temperature is raised to 72 degrees and free DNA nucleotides join to complementary base pairs
• DNA polymerase seals up the phosphodiester bonds along the backbone
• process is then repeated multiple times to produce identical DNA strands

Question 3

Electrophoresis

Answer 3

• cut DNA fragments need to be split up
• fragments move towards the anode due to their negative charge
• the smaller fragments will travel faster and further in a set time compared to larger fragments
• the DNA fragments are then transferred onto a membrane by Southern Blotting

Question 4

Fluorescent tags

Answer 4

• mean that the DNA is visible under the UV light
• forms the DNA profile

Question 5

Uses of DNA profiling

Answer 5

• forensics
• disease risk

Question 6

Disease Risk

Answer 6

• identifying individuals who are at risk of developing particular diseases
• specific gene markers can be identified and observed in DNA profiles

Question 7

Forensics

Answer 7

• PCR and DNA profiling is done on traces on DNA found at a crime scene
• obtained from saliva, blood, hair
• can then identify criminals

Question 8

DNA sequencing (chain termination)

Answer 8

• DNA is mixed with a primer, DNA polymerase, nucleotides and terminator bases
• strands separate by breaking the hydrogen bonds and primers anneal to the strands
• DNA polymerase starts to build new DNA strands by adding bases complementary to the original strand
• when terminator base is incorporated no more bases can bind after it so the fragment shortens
• repeated cycle to get DNA strands of various lengths
• separated by gel electrophoresis
• forms genome and can be analysed by scientists

Question 9

Pyrosequencing

Answer 9

• advances in gene technology
• lead to faster mapping of genomes
• light is produced when the correct base binds to the strand

Question 10

Computational biology

Answer 10

• uses data to build theoretical models
• analysis of large amounts of data
• helps identify genes linked to specific diseases in populations
• see evolutionary relationships between organisms

Question 11

Bioinformatics

Answer 11

• development of the software and computing tools needed to organise and analysis raw biological data
• make sense of enormous quantities of data

Question 12

Epidemiology

Answer 12

• sequencing human genomes to fin areas of specific genetic disease
• sequence pathogens genomes
• identify antibiotic resistant strains of bacteria
• track the progression of an outbreak

Question 13

Evolutionary relationships

Answer 13

• DNA sequences of different organisms can be compared
• how long ago two species diverged from a common ancestor
• build evolutionary trees

Question 14

Synthetic biology

Answer 14

• ability to sequence the genome of organisms
• understand how each sequence is translated into amino acids
• new area of biology

Question 15

Genetic engineering

Answer 15

• isolation of genes and suitable vectors

Question 16

Method of genetic engineering

Answer 16

• select most desired gene
• cut out the gene by using restriction enzymes to produce sticky ends
• then insert recombinant DNA into a vector ( bacterial plasmid)
• plasmid DNA is cut with the same restriction enzymes so both strands have complementary sticky ends
• then transfer the vector into a host cell by electroporation

Question 17

Genetic manipulation ( insect resistant soya beans)

Answer 17

• produce a toxic protein to pests tat eat the plant
• resistant to the common weed killer

Question 18

Positives of manipulation ( soya beans)

Answer 18

• increases the crop yield with less labour
• less expensive
• protects the environment
• reduce the amount of pest spraying

Question 19

Negative of manipulation ( soya beans)

Answer 19

• insects may become resistant to pesticides in GM crops
• other species may become damaged in the process

Question 20

Pharming

Answer 20

• production of human medicines

Question 21

Positives of pharming

Answer 21

• drugs are made in lager quantities
• more readily available

Question 22

Negatives of Pharming

Answer 22

• harmful side effects for the animal
• treating animals as assets to be treated how we chose

Question 23

Using pathogens for research

Answer 23

• to find treatments for diseases

Question 24

Positive of using pathogens for research

Answer 24

could find cures for previously untreatable disease

Question 25

Negative of using pathogens for research

Answer 25

- many become infected with the pathogen and cause an outbreak - GM pathogen may revert back and start an outbreak - if handled incorrectly then issues of biowarfare arise

Question 26

Patents

Answer 26

- impact less developed areas and farmers - cant afford to buy the patent to sell on the crop - cant afford to repeatedly plant the crop

Question 27

Somatic gene therapy

Answer 27

- uses body cells - replacing the mutant allele with healthy allele in the affected body cell - success in immune diseases, leukaemia's and myelomas - temporary solution - pass the faulty gene onto offspring

Question 28

Germ line gene therapy

Answer 28

- inserting the health allele into embryo straight after fertilisation - would pass on to offspring - illegal in human embryos - impacts are unknow - increase future implications ( cosmetic changes)