Gene technology

Question 1

Give an example of a drug made by genetically modified organisms

Answer 1

Human insulin

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 insuline

Question 3

What is a transgenic organism?

Answer 3

An organism that contains recombinant DNA

Question 4

What is recombinant DNA?

Answer 4

DNA that is from more than one organism.

Question 5

What is needed to make recombinant DNA?

Answer 5

DNA consisting of the desired gene, restriction endonuclease enzymes, plasmid, and DNA ligase.

Question 6

Describe the role of restriction endonuclease enzyme in making recombinant DNA

Answer 6

To recongise and cut sections of DNA on either side of the desired gene, isolating it.

Question 7

Describe the role of DNA ligase in making recombinant DNA

Answer 7

Forms phosphodiester linkages between two strands of DNA, making one new one.

Question 8

What is a vector?

Answer 8

Something used to transfer the desired gene into another organism.

Question 9

What is used as the vector to move the desired gene into other organisms?

Answer 9

Plasmids

Question 10

Why do we use plasmids as vectors?

Answer 10

They’re small and easy to use

Question 11

Explain how isolated DNA is placed into the plasmid

Answer 11

-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 (hydrogen bonds formed)
-Sealed with DNA ligase to create phosphodiester linkages

Question 12

What are sticky ends?

Answer 12

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

Question 13

How is recombinant DNA inserted into bacterial cells?

Answer 13

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

Question 14

Explain how electroporation facilitates bacterial cells to take up the transformed plasmid

Answer 14

A small electric current is applied to bacterial membranes so the membrane becomes porous and plasmids move into the cell.
This is achieved using calcium salts and rapid t° increase from 0 t 40°C

Question 15

What is the function of marker genes?

Answer 15

They help identify which bacteria has successfully taken up the plasmid.

Question 16

How would you check if a plasmid has taken up the antibiotic resistance gene?

Answer 16

If it has successfully taken up the gene then the bacteria will be antibiotic resistant.
If grown on antibiotic media, only the bacteria which have successfully transformed will survive.

Question 17

Outline the two types of gene therapy.

Answer 17

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

Question 18

How can recombinant DNA be inserted into host cells?

Answer 18

Viruses, microinjection, microprojectile, and liposome wrapping.

Question 19

What is the function of the microarray?

Answer 19

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

Question 20

Define bioinformatics

Answer 20

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

Question 21

What is the function of bioinformatics?

Answer 21

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

Question 22

What are the benefits of GM?

Answer 22

Higher crop yield, nutritional value, and pest resistance.
Less pesticide spraying
Crops grow in more adverse conditions
Can make medication and treatments quickly and cheaply e.g. human insulin
Can produce large quantities of enzymes cheaply.

Question 23

What are the risks of GM?

Answer 23

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
Companies could seek profit of it further and limit use of technology that could save lives.