5.2/3 Selective breeding + Genetic modification/genetic engineering

Question 1

what is transgenic organism?

Answer 1

organisms which have received genes from another species

Question 2

What are vectors?

Answer 2

vectors can be used to carry the DNA of one organism into another

Question 3

Genetic engineering, type 1 diabetes - producing more insulin

Answer 3

1. human insulin gene must be located on the chromosome (11)
2. gene is then cut from the rest of the chromosome using a special enzyme called a DNA restriction enzyme
3. A plasmid is removed from the bacterium (E. coil) and cut open with the same DNA restriction enzyme
4. Each DNA restriction enzyme cuts at a specific sequence of bases, producing short single stranded sections called sticky ends
5. The human insulin gene and plasmid join together due to complementary base pairing at the sticky ends. A DNA ligase enzyme forms bonds between the nucleotides to make this a single piece of DNA. We say the plasmid is now recombinant DNA - it is a combination from two different sources.
6. The plasmid is carrying the human DNA is referred to as a vector

Question 4

What is the function of ligase enzymes?

Answer 4

DNA ligase enzyme forms bonds between the nucleotides

Question 5

What is the plasmid carrying the human DNA referred to as?

Answer 5

a vector

Question 6

Why is a fermenter and the nutrient medium and air entering the system sterilised prior to use?

Answer 6

to prevent the growth of pathogens or competing microorganisms

Question 7

Why is transgenic bacteria placed into a fermenter?

Answer 7

in order to increase in number

Question 8

What are the optimum conditions needed to produce human insulin?

Answer 8

providing oxygen via the air line - for respiration
stirring the mixture to prevent clumping and a shortage of nutrients
monitoring temperature and cooling the fermenter if needed - optimum temperature for enzymes
adding more nutrient medium

Question 9

What happens once the insulin is secreted by the bacteria?

Answer 9

It is then collected from the fermenter, purified and distributed

Question 10

What are the two main stages of genetic modification in plants?

Answer 10

introducing the new gene or genes into plant cells
producing whole plants from just a few cells (tissue culture)

Question 11

What are the different traits that can be added to plants?

Answer 11

higher yield
ability to produce extra nutrients
resistance to extremes in weather
resistance to pests
resistance to disease/pathogens

Question 12

What are the advantages of genetic modified plants?

Answer 12

more precise method than selective breeding
higher crop yield/better food quality
less pesticide/herbicide used so less pollution
disease resistant/pest resistant/herbicide resistant

Question 13

What are the disadvantages of genetically modified plants?

Answer 13

not accepted by public
long term affects are unknown
may affect food chains or environment
reduces variation

Question 14

What are the steps to genetic modification in plants? (resistance against insect example)

Answer 14

insecticide gene created using recombinant DNA technology
plasmid vectors
digestion with restriction enzymes
cleaved DNA
cleaved vectors
growing plant cells take up insecticide gene from plasmid vectors
select for insecticidal cells
cell used for plant propagation
insects that feed on the plants will die