wrong questions

Question 1

What is the role of DNA ligase?

Answer 1

to join DNA/gene to the plasmid

Question 2

Describe how to insert copies of a desired gene into plasmids

Answer 2

1. Cut plasmid with restriction endonuclease
2. so that both have complementary sticky ends
3. mix together and add ligase to join the complementary sticky ends

Question 3

What can be inserted into the plasmid along with a gene to ensure that spider gene was only expressed in a certain are?

Answer 3

promotor region

Question 4

Explain the shape of a curve that shows the number of DNA molecules produced using PCR

Answer 4

1. Initially number of molecules doubling is low
2. Plateaus as no more nucleotides/primers

Question 5

Describe how scientists used radioactivelly labelled DNA probe to show that cells of a plant contained SUT1 gene

Answer 5

1. Extract DNA and add restriction endonucleases
2. Seperate fragments using electrophoresis
3. Treat dna to form single strands
4. the probebwill bind to SUT1 gene
5. Use autoradiography to show bound probe

Question 6

Suggestr why it is important to be able to identify the specific strain of a bacteria infecting a patient using a DNA probe?

Answer 6

1. To see if the strain is resisitant to any antibiotic
2. so they can prescribe effective antibiotic

Question 7

Suggest why it is important to be able to identify the specific strain of a bacteria infecting a patient using a DNA probe?

Answer 7

1. To see if the strain is resisitant to any antibiotic
2. so they can prescribe effective antibiotic

Question 8

Suggest how a virus that could only infect one species of an organism can now affect other speices of the same organism

Answer 8

1. Mutation in the viral DNA
2. Altered the viral attachement protein
3. Allows the attachment protien virus to bind

Question 9

Determining the genome of a virus could allow scientists to develop a vaccine

explain how

Answer 9

1. Could identify protiens that derive from the genetic code
2. they could then identify potential antigens to use in the vaccine

Question 10

How can DNA methyltransferases result in reduced effects of maliginat cancer

Answer 10

1. Reduces methylation
2. Tumor surpressor gene is transcribed/expressed
3. Prevents rapid/uncontrollable division

Question 11

Define what is meant by epigenetics?

Answer 11

• heritable changes in gene function
• without changes to the base sequence of DNA

Question 12

Explain how increased methylation could lead to cancer

Answer 12

1. Methyl groups added to a tumour supressor gene
2. The transcription of tumour suppressor genes is inhibited
3. Leading to uncontrolled cell division

Question 13

Describe how alterations to tumour suppressor genes can lead to the development of tumours

Answer 13

1. increased methylation
2. mutation in tumour supressor gene
3. tumour suppresor genes not transcribed
4. results in rapid/uncontrollable cell division

Question 14

Give one wat in which benign tumours differe from malignant tumours

Answer 14

cells of benign tumours cannot spread to other parts of the body, unable to metastasise

Question 15

Explain how the methylation of tumour suppressor genes can lead to cancer

Answer 15

1. Methlyation prevents transcription of the gene
2. Protein is not produced that prevents cell division
3. no control of mitosis

Question 16

What is a substituiton mutation?

Answer 16

replacement of a base by a different base