Gene Technology

Question 1

What does genetic engineering involve?

Answer 1

Genetic engineering involves transferring a gene from one organism to another. The organism that receives the new gene is called a transgenic organism.

Question 2

The main stages in genetic engineering involve:

Answer 2

• Identifying and removing a desired gene from one organism.
• Cutting open the DNA in another organism.
• Inserting the new gene into the DNA.
• Making sure that the gene works in the transgenic organisms.

Question 3

How is cutting and inserting of DNA achieved?

Answer 3

The cutting and inserting of DNA achieved using enzymes and often the transgenic organism can be cloned to produce identical copies.

Question 4

Restriction enzymes …

Answer 4

are used to cut open DNA. They leave several unpaired bases (single strands) on the cut end. This acts as a ‘sticky end’.

Question 5

Ligase Enzymes …

Answer 5

will join DNA strands because the ‘sticky ends’ on each cut section of DNA can join by complementary base pairings.

Question 6

Bacteria can be used in genetic engineering to produce human insulin. This involves:

Answer 6

• Cutting the gene for producing human insulin out out of human DNA.
• Cutting open a loop of bacterial DNA.
• Inserting the insulin gene into the loop.
• Inserting the loop into a bacterium.

Question 7

How are bacteria cultured?

Answer 7

Many copies of the bacteria are cultured by cloning and large quantities of insulin are harvested.

Question 8

What are plasmids?

Answer 8

The loops of DNA used in this process are called plasmids. They are found in the cytoplasm of bacteria and because they can be taken up by bacteria, they can be used as vectors for genes.

Question 9

To find out whether a bacterium has taken up a plasmid…

Answer 9

• An assaying technique is used:
  
  • Scientists add genes that make the bacteria resistant to antibiotics.
  • The bacteria are then flooded with the antibiotics by being grown on nutrient agar containing the antibiotic.
  • Scientists then choose the bacteria that survive.

Question 10

Why are DNA ‘fingerprints’ are produced?

Answer 10

• DNA ‘fingerprints’ can be produced to identify individuals. They can be stored to help identify people who commit crimes and prove the innocence of others.
• However, some people are worried that they may be used for a variety of reason such assessing the likelihood of a person developing a disease. The information could be used as a reason to withhold life insurance.

Question 11

The stages in the production of a DNA ‘fingerprint’ include:

Answer 11

• Extracting DNA from a sample, such as blood.
• Cutting up or fragmenting the DNA using restriction enzymes.
• Separating the fragments using electrophoresis
• Making the fragments visible using a radioactive probe