Topic 8 Assessment Booklet
Marks = 114 Time Allowed 158 minutes
Q1.
People suffering from pituitary dwarfism do not make enough human growth hormone
(HGH). They can be treated using injections of HGH.
A geneticist wants to transform the bacterium, Escherichia coli, to make HGH by adding
the gene coding for HGH.
The geneticist could obtain the HGH gene using any one of three methods.
1. Use restriction enzymes to cut out a fragment of DNA containing the HGH gene from
a human genome.
2. Convert mRNA for HGH into cDNA using reverse transcriptase.
3. Create the HGH gene using a ‘gene machine’.
(a) The geneticist decided not to use restriction enzymes to cut out a fragment of DNA
containing the HGH gene from a human genome. She made this decision because
only methods 2 and 3 would produce DNA that E. coli could use to make HGH.
Explain why only methods 2 and 3 would produce DNA that E. coli could use to
make HGH.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) The geneticist concluded it would be faster to create the HGH gene using a gene
machine than by using reverse transcriptase to convert mRNA for HGH into cDNA.
Suggest why the geneticist reached this conclusion.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
(c) After obtaining copies of the HGH gene, the geneticist will attempt to insert them into
plasmid vectors.
Describe how the geneticist would attempt to insert copies of the HGH gene into
these plasmids.
Page 1 of 32
, ___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(d) The geneticist plans to use the plasmids containing the HGH gene to try to
transform cells of E. coli. She knows that some E. coli might not take up the plasmid.
To enable her to identify which bacteria have taken up the plasmid with the HGH
gene, the plasmids she intends to use contain a gene that codes for a green
fluorescent protein (GFP). Bacteria that contain this plasmid glow green under UV
light.
Suggest one advantage of using this gene for GFP to identify bacteria that have
taken up plasmids.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
The diagram below shows part of the plasmid containing the gene that codes for GFP. It
also shows the roles of two genes that control the GFP gene.
(e) Arabinose is a sugar that can bind to the araC protein.
Use information in the diagram to suggest why the geneticist must include arabinose
in the agar on which she hopes to grow E. coli containing the transgenic plasmids.
___________________________________________________________________
Page 1 of 32
, ___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 9 marks)
Q2.
(a) Explain how the methylation of tumour suppressor genes can lead to cancer.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
Scientists investigated a possible relationship between the percentage of fat in the diet
and the death rate from breast cancer in women from 10 countries.
Their data is shown in the table below.
Percentage of fat in Death rate of women
diet of population
from breast cancer
per 100 000 women
9.5 1.5
15.0 7.0
20.0 12.0
25.0 9.0
32.0 15.0
35.0 8.0
35.0 20.0
40.5 18.0
43.0 24.0
45.0 26.0
Page 1 of 32
, (b) Describe how you would plot a suitable graph of these data. Explain your choice of
type of graph.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(c) What can you conclude from these data?
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 8 marks)
Q3.
(a) Define what is meant by epigenetics.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) In eukaryotes, transcription of target genes can be stimulated or inhibited when
specific transcriptional factors move from the cytoplasm into the nucleus.
Oestrogen, methyl groups and acetyl groups are control factors that can play a role
in initiating transcription.
Complete the table to show features of these control factors.
Put a tick (✔) in the box if the control factor shows the feature.
Feature
Control factor Binds with DNA Binds with protein
Page 1 of 32
Marks = 114 Time Allowed 158 minutes
Q1.
People suffering from pituitary dwarfism do not make enough human growth hormone
(HGH). They can be treated using injections of HGH.
A geneticist wants to transform the bacterium, Escherichia coli, to make HGH by adding
the gene coding for HGH.
The geneticist could obtain the HGH gene using any one of three methods.
1. Use restriction enzymes to cut out a fragment of DNA containing the HGH gene from
a human genome.
2. Convert mRNA for HGH into cDNA using reverse transcriptase.
3. Create the HGH gene using a ‘gene machine’.
(a) The geneticist decided not to use restriction enzymes to cut out a fragment of DNA
containing the HGH gene from a human genome. She made this decision because
only methods 2 and 3 would produce DNA that E. coli could use to make HGH.
Explain why only methods 2 and 3 would produce DNA that E. coli could use to
make HGH.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) The geneticist concluded it would be faster to create the HGH gene using a gene
machine than by using reverse transcriptase to convert mRNA for HGH into cDNA.
Suggest why the geneticist reached this conclusion.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
(c) After obtaining copies of the HGH gene, the geneticist will attempt to insert them into
plasmid vectors.
Describe how the geneticist would attempt to insert copies of the HGH gene into
these plasmids.
Page 1 of 32
, ___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(d) The geneticist plans to use the plasmids containing the HGH gene to try to
transform cells of E. coli. She knows that some E. coli might not take up the plasmid.
To enable her to identify which bacteria have taken up the plasmid with the HGH
gene, the plasmids she intends to use contain a gene that codes for a green
fluorescent protein (GFP). Bacteria that contain this plasmid glow green under UV
light.
Suggest one advantage of using this gene for GFP to identify bacteria that have
taken up plasmids.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
The diagram below shows part of the plasmid containing the gene that codes for GFP. It
also shows the roles of two genes that control the GFP gene.
(e) Arabinose is a sugar that can bind to the araC protein.
Use information in the diagram to suggest why the geneticist must include arabinose
in the agar on which she hopes to grow E. coli containing the transgenic plasmids.
___________________________________________________________________
Page 1 of 32
, ___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 9 marks)
Q2.
(a) Explain how the methylation of tumour suppressor genes can lead to cancer.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
Scientists investigated a possible relationship between the percentage of fat in the diet
and the death rate from breast cancer in women from 10 countries.
Their data is shown in the table below.
Percentage of fat in Death rate of women
diet of population
from breast cancer
per 100 000 women
9.5 1.5
15.0 7.0
20.0 12.0
25.0 9.0
32.0 15.0
35.0 8.0
35.0 20.0
40.5 18.0
43.0 24.0
45.0 26.0
Page 1 of 32
, (b) Describe how you would plot a suitable graph of these data. Explain your choice of
type of graph.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(c) What can you conclude from these data?
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 8 marks)
Q3.
(a) Define what is meant by epigenetics.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) In eukaryotes, transcription of target genes can be stimulated or inhibited when
specific transcriptional factors move from the cytoplasm into the nucleus.
Oestrogen, methyl groups and acetyl groups are control factors that can play a role
in initiating transcription.
Complete the table to show features of these control factors.
Put a tick (✔) in the box if the control factor shows the feature.
Feature
Control factor Binds with DNA Binds with protein
Page 1 of 32
