B6h: Gene technology

Question 1

What are transgenic organism

Answer 1

new type of organism produced by genetic engineering

Question 2

Main stages in genetic engineering(6)

Answer 2

1. identification of desired gene in 1 organism
2. removal of gene from DNA
3. cutting open DNA in another organism
4. inserting new gene into the DNA of 2nd organism
5. make sure the gene works in transgenic organism
6. transgenic organism can be cloned to produce identical copies

Question 3

How is the cutting and inserting of DNA achieved?

Answer 3

using enzymes

Question 4

Why can genes from one organism work in another?(2)

Answer 4

because genetic code is universal; same 4 bases used in DNA of all organisms
-genes from one organism will produce the same protein in another organism

Question 5

Restriction enzymes (2)

Answer 5

cuts open DNA, leaving unpaired bases exposed on ends of strands - sticky ends

new gene also cut by restriction enzyme, creating sticky ends, thus they will fit into vector’s cut DNA; sticky ends join together, allowing ligase enzymes to rejoin DNA strands

Question 6

How can bacteria be used in genetic engineering to produce human insulin? (7)

Answer 6

1. gene for producing human insulin cut out of human DNA
2. loop of bacterial DNA (plasmid) cut open with restriction enzyme, leaving sticky ends
3. insulin gene inserted into plasmid, sticky ends allow ligase enzymes to rejoin DNA strands
4. plasmid (vectors) inserted into a bacterium
5. bacteria then able to produce insulin
6. these transgenic bacteria cultured by cloning
7. allowing large quantities of insulin harvested

Question 7

What are plasmids

Answer 7

loops of DNA in cytoplasm of bacteria

Question 8

What can plasmids be used as and why(2)

Answer 8

can be used as vectors in GE - something that carries gene into another organism

because they can be taken up by bacteria

Question 9

What can be used to check that new gene have been correctly transferred

Answer 9

Assaying techniques

Question 10

Arguments for storage of DNA fingerprints

Answer 10

police can build up large dbase of DNA fingerprints; esay to compare forensic evidence w/ records of many suspects, making it easier to solve crimes

Question 11

Arguments against storage of DNA fingerprints (3)

Answer 11

invasion of privacy; records should not be kept if innocent

false positives may occur if errors made in procedure or if data misinterpreted

information may be used for other purposes (e.g. assessing the likelihood of a person developing a disease, which could be used as a reason to withhold life insurance)

Question 12

Stages in the production of a DNA fingerprint (4)

Answer 12

1. extraction of DNA from sample of human tissue
2. DNA cut into fragments with restriction enzymes; because people have different DNA, restriction enzymes cut in different places, prod fragments of different lengths
3. electrophoresis to seperate fragments according to size; smaller fragments travel further
4. the fragments are made visible using a radioactive probe so patterns could be observed