2014 Notes from the Marking Centre – Senior Science
Introduction
This document has been produced for the teachers and candidates of the Stage 6 Senior Science course. It contains comments on candidate responses to the 2014 Higher School Certificate examination, highlighting their strengths in particular parts of the examination and indicating where candidates need to improve.
This document should be read along with:
- the Senior Science Stage 6 Syllabus
- the 2014 Higher School Certificate Senior Science examination
- the marking guidelines
- Advice for students sitting for HSC science examinations
- Advice for HSC students about examinations
- other support documents developed by the Board of Studies, Teaching and Educational Standards NSW to assist in the teaching and learning of Senior Science in Stage 6.
Section I
Part B
Candidates showed strength in these areas:
- identifying ‘sound’ as a form of energy going into a microphone (Q.21)
- identifying the properties of biomedical cement (Q.22)
- understanding the role of synovial fluid in lubricating a joint (Q.22)
- recognising the benefits of using optical fibres for communication (Q.23)
- explaining the observable result of an experiment (Q.24 (a))
- knowing the difference between a suspension and an emulsion (Q.24 (b))
- knowing the features and roles of a range of communication systems (Q.25)
- drawing graphs with appropriate linear scales and accurately plotting data from a table on a graph (Q.26 (a))
- explaining the benefits of minimal and non-invasive medical techniques (Q.27)
- knowing about different communication systems (Q.28)
- understanding the role of pH in the digestive system (Q.29)
- understanding the role of life support systems, such as the heart–lung machine, the pacemaker and kidney dialysis (Q.30)
- knowing how medications are released in the body, eg sub-dermal implants (Q.30).
Candidates need to improve in these areas:
- identifying the variety of energy changes involved in radio communication (Q.21)
- understanding how total internal reflection occurs (Q.23)
- knowing the difference between an emulsion, a colloid and a solution (Q.24)
- understanding the meaning of the term ‘bio-degradable’ (Q.24)
- explaining how communication systems often need to be linked together (Q.25)
- interpreting graphs (Q.26 (b))
- using scientific terminology (Q.27)
- constructing flow charts (Q.29)
- understanding the purpose of the enteric coating on some tablets (Q.29 (b))
- understanding the difference between the role of different life-support systems (Q.30)
- understanding the role of some parts of the body (Q.30)
- knowing that medications are circulated throughout the body, not just targeting particular organs (Q.30).
Section II
Question 31 – Polymers
Candidates showed strength in these areas:
- naming a natural polymer (part (a))
- naming properties of polystyrene that make it suitable as a packaging material (part (a))
- distinguishing between the properties of thermosetting and thermoplastic polymers when heated (part (a))
- identifying the benefits of using bar graphs (part (b))
- describing the harmful effects of plastics on the environment (part (c))
- recognising the need for controlled variables in an experiment (part (d))
- demonstrating knowledge of natural and synthetic fibres and their impact on society (part (e)).
Candidates need to improve in these areas:
- identifying the limitations of bar graphs (part (b))
- recognising the difference between biodegradability and recyclability (part (c))
- identifying the independent and dependent variables in an experiment (part (d))
- understanding the difference between validity and reliability (part (d))
- linking the properties of polymers with their uses in society (part (e))
- describing the properties of natural and synthetic fibres (part (e)).
Question 32 – Preservatives and Additives
Candidates showed strength in these areas:
- knowing specific microbes that cause food spoilage (part (a))
- knowing the temperature conditions in which microbes grow, are inhibited or are killed (part (a))
- identifying reasons for labelling food products (part (c))
- distinguishing between physical and chemical preservation techniques (part (e)).
Candidates need to improve in these areas:
- identifying the independent and dependent variables in an experiment (part (d))
- describing how preservation techniques reduce or eliminate the growth of microbes (part (e)).
Question 33 – Pharmaceuticals
Candidates showed strength in these areas:
- understanding the sequence of a reflex arc (part (a))
- identifying the features of bar graphs (part (b))
- describing the work of Pasteur or Koch (part (c))
- describing the action of analgesics and antibiotics (part (e)).
Candidates need to improve in these areas:
- determining the appropriateness of using a bar graph to present different data (part (b))
- linking the ideas and work of Pasteur or Koch to our understanding of bacteria (part (c))
- identifying the independent and dependent variables in an experiment (part (d))
- understanding the difference between validity and reliability (part (d)).
Question 34 – Disasters
Candidates showed strength in these areas:
- explaining why specific definitions and terminology are used in insurance contracts (part (a))
- outlining the effects of the slope of the land on the speed and spread of a bushfire (part (a))
- identifying benefits and problems of using bar graphs (part (b))
- understanding the importance of satellite photographs in interpreting weather patterns (part (c))
- identifying a problem with the outlined experiment (part (d))
- describing how warning devices and emergency services are used to minimise the effect of fires (part (e)).
Candidates need to improve in these areas:
- differentiating between a ‘control’ and ‘controlled variables’ (part (d))
- identifying the independent and dependent variables in an experiment (part (d))
- understanding what is meant by the terms ‘validity’, ‘reliability’ and ‘accuracy’ (part (d))
- making clear judgements as to how warning devices and emergency services minimise the effect of fires (part (e)).
Question 35 – Space Science
Candidates showed strength in these areas:
- understanding the effects of circadian rhythms and describing techniques to counteract these effects (part (a))
- identifying the effect of microgravity on muscles (part (c))
- knowing about spacecraft, satellites and telescopes (part (e)).
Candidates need to improve in these areas:
- understanding the meaning of circadian rhythms (part (a))
- identifying the independent and dependent variables in an experiment (part (d))
- understanding the difference between validity and reliability (part (d)).
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