Bio Technology

Question 1

Restriction Enzymes

Answer 1

First isolated from bacteria
Acts as molecular scissors
They cut DNA when they encounter a specific sequence (usually 4-6 bases)
known as a recognition site
Each restriction enzyme has a specific recognition site

Question 2

DNA Ligase

Answer 2

Is an enzyme which is used to glue segments of DNA together

Acts a molecular glue

Question 3

Plasmids

Answer 3

Extra chromosomal DNA isolated from bacterial cells
Often carry useful genes such as antibiotic resistance
Transfer desired genes into the genome of another organism
Vectors involved

Question 4

Polymerase Chain Reaction

Answer 4

Used to amplify vast quantities of identical DNA

Equipment= primers, DNA polymerase, DNA sample, nucleotides and thermocycler

Question 5

Denaturation (polymerase chain reaction)

Answer 5

Mixture is heated to 95 degrees

Causes DNA sample to denature become single stranded

Question 6

Annealing (polymerase chain reaction)

Answer 6

Temp is changed to 50-60 degrees

Allows DNA primers to be attached to single stranded DNA

Question 7

Extension (polymerase chain reaction)

Answer 7

Temp changes to 72 degrees

Taq polymerase begins to add free nucleotides using DNA as template

Question 8

Repeat (polymerase chain reaction)

Answer 8

Cycle is repeated many times producing large quantities of DNA

Question 9

Gel Electrophoresis

Answer 9

Compares DNA/gene sequences

Question 10

Gel Electrophoresis

Answer 10

1. DNA is extracted and amplified using PCR
2. DNA samples are then treated with the same restriction enzymes
3. Gel is covered with a buffer solution
4. DNA is mixed with loading dyes in wells
5. An electric current is run through the buffer/gel.
6. DNA has a negative charge
7. Causes DNA to move towards the positive electrode
8. Large fragments more slow/ small fragments more fast
9. Viewed under UV light
10. Banding patterns compared for similarities

Question 11

Genetically Modified Organism (GMO)

Answer 11

Their DNA has been altered in some way.
E.g foreign DNA added
Deleting/removing DNA

Question 12

Transgenic

Answer 12

Has been genetically altered to contain DNA from another species

Question 13

Super Salmon

Answer 13

Genetically modified Atlantic salmon
A growth hormone regulating gene from chinook salmon with a promoter gene from ocean pout were added to Atlantic salmon genes

Question 14

Golden Rice

Answer 14

gene taken from daffodil and inserted into the genome of a temperate strain of rice to biosynthesise b carotene

Question 15

Sticky ends

Answer 15

Produces a cut resulting in a single stranded overhang

Question 16

Blunt ends

Answer 16

No single strand over hang

Question 17

Substitution

Answer 17

When a single base is swapped with a different one
Silent= single change results in same amino acid produced
Non Sense= results in stop codon
Mis Sense= results in a different amino acid

Question 18

DNA Microarray

Answer 18

Measure if genes are ‘switched on or off’
DNA has binded to the primer the gene is switched on
Secondary colour= hybridisation
Advantage= can screen many genes at once therefore increases efficiency
Structure= similar to small glass cover slip, but contains a series of wells/divots. Fluorescent marks are used and read by a computer

Question 19

Steps DNA Microarray

Answer 19

• primers are added to each well
• each primer corresponds to a known gene sequence
• fluorescent marker is added to the primer
• subject DNA is washed over DNA chip (second fluorescent marker added)
• complementary DNA binds
• chip is read by a computer