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HSC Biology 9.4 Search for Better Health Example Questions
Markers comments and marking guidelines
Example Question 1: (2013 HSC Biology exam) Question 21 (4 marks)
Sample answer:
The T helper cell is part of an initial response to an antigen, releasing chemicals to stimulate
growth of B cells that respond to the antigen. A T memory cell responds differently,
interacting initially with an antigen but remaining dormant until the next time the body is
infected, when it is quickly activated so that there is a faster response to the antigen. cells.
Markers’ guidelines Question 21
Criteria
Marks
• Names two types of T cells
• Provides characteristics and features of the roles of each of the T cells, in
the immune response in humans
• Names two types of T cells
• Provides the characteristics and features of the roles of one of the T cells
4
3
• Provides the characteristics and features of the role of one named T cell
OR
2
• Names two types of T cells
• Provides some relevant information about T cells
1
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HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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Example Question 2: (2013 HSC Biology exam) Question 24 (7 marks)
Sample answers:
a)
b) Controls in microbial experiments allow us to validate the results. The control ensures
that the microbial growth is a result of experimental conditions rather than contamination.
For example, when testing the presence of microbes in food, the control agar plate is left
unopened / unexposed. No growth in the control culture plate will make sure the microbial
growth in experimental plates is from food rather than from the contamination of nutrient
agar.
Markers’ guidelines Question 24 (a)
Criteria
• Provides flowchart including arrows, words, and/or diagrams
Marks
4
• Provides all critical features of Pasteur’s experiment including a control
• Provides a list with all critical features
3
• Lists three features in the correct sequence
2
• Lists two connecting features (linked by an arrow)
1
OR
2
HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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• Provides three features of the experiment
Markers’ guidelines Question 24 (b)
Criteria
Marks
• Makes evident the relationship between the use of controls and microbial
experiments, including the importance to increasing the validity
3
• Provides a reason for using controls and identifies a control for a
microbial experiment
2
OR
• Provides a reason for using a relevant control and indicates its importance
to increasing validity
OR
• Provides two reasons for using controls
OR
• Provides a relevant control and indicates its importance to increasing
validity
• Identifies a relevant control for a microbial experiment
1
OR
• Provides a reason for using a relevant control
OR
• Indicates the importance of using controls to increase validity
3
HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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Example Question 3: (2012 HSC Biology exam) Question 26 (5 marks)
Markers’ Comments:
In better responses, candidates analysed the methodology by identifying strengths and
weaknesses in each part of the study and supplied supporting reasons. In weaker responses,
candidates only identified strengths and/or weaknesses for some parts of the study.
Sample answer:
The design of this study cannot validly lead to a link between disease and its likely causes. A
valid questionnaire is good but the number of subjects is low and only confined to the
workplace. The sample should be larger and broader. Ideally, the study should have a
variety of equal categories, eg age, ethnicity, not just male: females equal. Participants
should not be eliminated on the basis of their answers as this reduces the s cientific validity.
Any checks should be consistent, with a definite purpose related to the study, eg lungs
checked. The final data should be peer reviewed for publication.
Markers’ guidelines Question 26
Criteria
Marks
• Analyses the methodology of epidemiology
• Identifies strengths and/or weaknesses in each part of the study from the
information provided
5
• Analyses the methodology of epidemiology
• Identifies strengths and/or weaknesses in most but not all parts of the study
(does not address all points of the study) from the information provided
4
• Demonstrates a basic knowledge of the methodology of epidemiology
• Identifies strengths or weaknesses in some parts of the study OR identifies
strengths and weaknesses in one part of the study
• Recalls a feature of epidemiology
• Identifies a weakness or a strength of the method
3
2
• Identifies a feature of epidemiology
OR
1
• Identifies a weakness or a strength of the method
4
HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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Example Question 4: (2011 HSC Biology exam) Question 24 (5 marks)
Markers’ Comments:
a. In better responses, candidates identified a viral disease controlled by the use of a
vaccine. In weaker responses, candidates identified viral diseases not controlled by
the use of a vaccine or a disease caused by a pathogen other than a virus.
b.
i.
In better responses, candidates outlined how a feature of the viral vaccine –
prepared as shown in the flowchart – initiated a named immune response. In
weaker responses, candidates failed to name an immune response or made a
general statement about the body’s response to a vaccine.
ii.
In better responses, candidates explained one correct procedure from the
flowchart that would ensure the safety of the prepared vaccine. Weaker
responses often only identified a correct procedure in the flowchart.
Sample answer:
a) Polio
b) ii) The protein coat of the virus contains the surface antigens of the virus. Just as the
immune system detects the antigens on the whole virus, it also detects the antigens on the
protein coat and in the same way. Thus plasma cells will be developed to produce an
antibody to this antigen, and memory B cells will likewise be developed. In this way, if the
whole virus subsequently invades the body, antibody levels would quickly build to inactivate
the virus
b) ii) Removing nucleic acid from the virus ensures that host cells will not be made to
replicate viral nucleic acid and make viral protein. Thus the virus cannot multiply in the host.
OR
Suspending protein in a saline solution ensures the liquid is isotonic to blood, and blood
cells will not be altered by the injection of the vaccine solution.
Markers’ guidelines Question 24 a)
Criteria
• Identifies a viral disease that is controlled by the use of a vaccine
Marks
1
Question 24 b) i)
Criteria
Marks
• Indicates ONE main feature of the viral vaccine and links it to a named
immune response
2
• Indicates ONE main feature of a vaccine
1
OR
5
HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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• Names an immune response
Question 24 b) ii)
Criteria
Marks
• Identifies a correct step from the flowchart and relates it to safe use of
the vaccine
2
• Identifies a correct step from the flowchart
1
OR
• Relates it to a safe use of the vaccine
6
HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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Example Question 5: (2011 HSC Biology exam) Question 27 (4 marks)
Markers’ Comments:
In better responses, candidates clearly outlined four features relevant to an epidemiological
study. Candidates outlined features such as large sample size, data collection, analysis and a
cause and effect relationship related to the non-infectious disease in the aged care
homes.In weaker responses, candidates included an extensive list of data to be collected
rather than addressing the main features of an epidemiological study.
Sample answer:
• Large sample size
• Control of variables (across gender, age)
• Data that is collected and analysed:
– diet
– hygiene
– location/environment
– personal history/lifestyle
• Data analysis
– compare for common data with and without disease
– look for common data in people who have disease
Markers’ guidelines
Criteria
Marks
• Sketches in general terms FOUR features of an epidemiological
study to identify the cause of the disease
4
• Sketches in general terms features of an epidemiological study to
identify the cause of the disease
3
• Describes a feature of an epidemiological study to identify the
cause of the disease
2
• Identifies a feature of an epidemiological study
1
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Example Question 6: (2010 Paper) Question 22 (6 marks)
Markers’ Comments:
a. In better responses, candidates demonstrated good graphing skills, identified
dependent and independent variables, plotted points correctly and drew lines or
curves of best fit. In weaker responses, candidates plotted data on the incorrect axis
or used a column graph.
b. The better responses identified the relevant human processes linked to the data and
related this to the effect of a decrease in biodiversity. In weaker responses,
candidates had difficulty relating the data and effect of the human process on
biodiversity.
Sample answers:
a)
b) Humans develop drugs to kill pathogens. The data show that the malaria pathogen
becomes resistant to these drugs which become less effective with their use. This occurs
because the drug is selecting for resistant pathogens and this reduces the biodiversity of the
population.
Markers’ guidelines Question 22 a)
Criteria
Marks
• Correctly plots data, labels axes and provides line or curve of best fit 3
• Provides some of these features e.g. Does not label an axis properly
or does not plot 1 set of data correctly
2
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HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines
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• Provides a correct feature
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Question 22 b)
Criteria
Marks
• Correctly identifies the human process
3
• Correctly links their response to the data 3
• Correctly links the use of drugs to a change in biodiversity
• TWO of the above
2
• ONE of the above
1
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Example Question 7: (2002 Paper) Question 19 (5 marks)
Markers’ Comments:
Most candidates indicated a reasonable understanding of nuclear chemistry. A significant
number of candidates wrote excessively long answers. Such long answers are likely to have
missed the point of the question or provide responses that contain contradictions.
(a) In this part most candidates wrote too much, going well beyond the allocated space.
Many candidates erroneously included electrons in their answer to a question on nuclear
stability.
(b) The majority of candidates interpreted the graph well.
Markers’ guidelines Question 19 a)
Criteria
Marks
Correctly identifies the features that make a nucleus unstable
2
Identifies that ‘protons’ and ‘neutrons’ are found in nucleus
1
OR
Correctly describes one condition under which a nucleus is unstable
Markers’ guidelines Question 19 b)
Criteria
Marks
Describes alpha and beta decay using examples from the flow
diagram
3
Describes alpha decay using an example from the flow diagram
2
OR
Describes beta decay using an example from the flow diagram
OR
Describes alpha and beta decay
Describes either alpha or beta decay
1
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HSC Chemi stry 9.2.5 Production of Materials Example Questions – Ma rking Guidelines