gene tech

Question 1

what is a transgenic organism

Answer 1

an organism that contains recombinant DNA

Question 2

Give an example of how drugs can be produced using genetically modified organisms

Answer 2

Bacteria used to produce human insulin. ● Working human insulin gene inserted into bacterial plasmids which are taken up by bacteria, then transcribed and translated to produce insulin.

Question 3

what is recombinant dna

Answer 3

dna that is from more than one organism

Question 4

fucntion of restriction endonuclease enzyme

Answer 4

to recognise and cut sections of DNA either side of the desired gene, isolating it.

Question 5

Vector

Answer 5

somethimg used to transfer the desired gene into another organism

Question 6

what is used as the vector to transfer desired gene

Answer 6

Plasmid

Question 7

Explain how the isolated DNA is placed into the plasmid

Answer 7

The plasmid and desired gene are cut by the same restriction endonuclease enzyme creating complementary sticky ends.
● Desired gene is amplified using PCR.
● Base pairing between complementary sticky ends takes place (form hydrogen bonds).
● Sealed with DNA ligase to create phosphodiester linkages

Question 8

what are sticky ends

Answer 8

Small sections of unpaired and overhanging bases at the end of a DNA fragment.

Question 9

How is recombinant DNA inserted into bacterial cells?

Answer 9

Electroporation is used to stimulate bacterial cells to take up transformed plasmids.

Question 10

function of marker genes

Answer 10

They help identify which bacteria has successfully taken up the plasmid

Question 11

two types of gene therapy

Answer 11

Germ line therapy - inserting recombinant DNA by modifying fertilised egg cells. This is banned in humans. Somatic cell - replacing only mutant body cell with healthy adult body cells and is allowed.

Question 12

Outline the ways in which recombinant DNA can be inserted into host cells

Answer 12

Viruses - these infect host cells and insert their RNA and DNA into their genome Microinjection - using a very fine glass pipette to physically insert the desired DNA into fertilised egg cells Microprojectile - inserting the DNA by firing it at very high speed into the cell Liposome wrapping - liposomes can fuse with the cell surface membrane and release their contents inside of the cell and have been used to deliver recombinant DNA to cells

Question 13

function of microarray

Answer 13

It determines which genes are expressed within the cells of an organism.

Question 14

Outline how microarrays can be used to identify active genes

Answer 14

An array is set up containing the cDNA of the gene(s) being tested for the presence of. The person’s fragmented DNA sample is fluorescently labelled then washed over the array; if they contain the allele for any of the gene probes on the array then their DNA will hybridise to the probe and fluoresce, showing the gene is present.

Question 15

define bioinformatics

Answer 15

Developing of software and computing tools to collect and analyse complex biological data such as genetic codes.

Question 16

function of bioinformatics

Answer 16

Build and store databases of genomes and gene sequences of thousands of organisms. Used to compare genetic relationships between species and within species.

Question 17

benefits of gm crops

Answer 17

GM crops are modified to have higher yield, increased nutritional value and pest resistance which helps reduce malnutrition in 3rd world countries. ● Pest resistant GM crops means less pesticide spraying which is good for the environment and helps poor farmers. ● GM crops are able to be grown in more adverse conditions. ● Can make medication & treatments quickly and cheaply e.g. human insulin. ● Can potentially use gene therapy for treatment of human disorders. ● Can produce large quantities of enzymes cheaply which can be used as industrial catalysts

Question 18

risks of gm

Answer 18

Can lead to monoculture = reduce biodiversity. ● Pests may become resistant to pesticide in GM crops. ● Transferred gene may spread to wild population causing problems like superweeds. ● GM of humans is unethical and can lead to designer babies and prejudices against those with genetic disorders. ● Companies who own GM technology could seek profit of it further and limit use of technology that could save lives.