Biotechnology

Question 1

What is gene technology

Answer 1

analysis of DNA, genetic engineering, etc

Question 2

Genetic engineering

Answer 2

Artficially adding or removing genes, or changing the way genes work

Question 3

List the benefits of genetically modified organisms?

Answer 3

increasing crop/livestock production
preventing and fighting disease
reducing pollusion
producing new products

Question 4

What type of ends do restriction enzymes produce

Answer 4

Sticky ends

Blunt ends

Question 5

What is PCR?

Answer 5

Polymerase chain reaction

Makes many copies of DNA identical to trace samples

Question 6

Steps in PCR

Answer 6

1. Separate DNA strands by heating at 98°C for 5 mins
2. Add primers (short RNA strands provide a starting sequence for DNA replication), & nucleotides (A, T, G, C) & DNA polymerase.
3. Incubate by cooling to 60°C for a few mins while primers attach to single-stranded DNA. DNA polymerase synthesises complementary strands.
   Repeat for ~25 cycles

Question 7

What is gel electrophoresis?

Answer 7

Uses size and charge to separate DNA

Question 8

Steps in gel electrophoresis

Answer 8

Sample is taken
PCR to amplify amount of DNA
Restriction enzyme cut DNA into fragments of various length
Markers used to show all possible fragments
Samples are added to wells at the origin end, and electric current is switched on where it attracts DNA towards positive electrode

Question 9

How do analyse the DNA in gel electrophoresis

Answer 9

Molecules of different 
sizes (molecular weights) 
become separated 
(spread out) on the 
gel surface.

Question 10

Steps for gene cloning using bacterial plasmid vectors

Answer 10

1. Gene (DNA fragment) is isolated from human cells.
2. DNA & plasmids are treated with the same restriction enzyme to produce identical sticky ends.
3. Restriction enzyme cuts the plasmid DNA at its single recognition sequence
4. Mix the DNAs together & add the DNA ligase to bond the sticky ends.
5. Recombinant plasmid is introduced into a bacterial cell by simply adding the DNA to a bacterial culture where some bacteria take up the plasmid.
6. Bacterial cell reproduces millions of times making millions of copies of the gene.

Question 11

Steps for gene cloning using viruses

Answer 11

1. A gene is isolated from a human cell.
2. An bacteriophage vector is selected to infect the target cell.
3. Human and the viral DNA are cut with the same restriction enzyme.
4. Mix the DNAs together and the sticky ends attach. Add ligase to bond the sticky ends.
5. The recombinant DNA is packaged into phage particles by mixing with phage proteins.
6. Assembled infect a bacterial host cell.
7. Viral genes and enzymes replicate the recombinant DNA within the bacterial host cell.
   The bacterial host cell succumbs to the viral infection. The cell ruptures (lysis) and thousands of phages, each with recombinant DNA, are released to infect neighbouring bacteria.

Question 12

What is a transgenic organism

Answer 12

An organism that develops from a ell that has a foreign gene

Question 13

Uses of DNA profiling

Answer 13

Shows the genetic relatedness of different organisms.