Investigating Science 2019 HSC exam pack

Students should:

• address the key words and concepts being assessed in the question
• be familiar with the working scientifically skills, that are an essential aspect of this course.

Question 21

In better responses, students were able to:

• identify that bacteria were present in biopsies of patients who presented with peptic ulcer symptoms (a)
• link the observation of the bacteria in multiple patients with peptic ulcers as the actual cause of the disease (a)
• specifically state that Marshall ingested bacteria and treated himself with antibiotics (b).

Areas for students to improve include stating:

• that a large sample size is needed when drawing cause-and-effect conclusions about the nature of peptic ulcers (b)
• the specific symptoms of peptic ulcers, indicating that Marshall had most likely developed the disease (b).

Question 22

In better responses, students were able to:

• select the correct axes for the independent and dependent variables and sketch the straight-line relationship (a).

Areas for students to improve include:

• ensuring that the independent variable is placed on the x-axis and that the dependent variable is placed on the y-axis (a)
• using correct units that relate to the question, for example, car speed is usually measured in kilometres per hour rather than metres per second (a)
• describing why some variables need to be kept constant in a fair test (b).

Question 23

In better responses, students were able to:

• address validity by mentioning controlling variables and/or clearly identifying the independent variable
• show a clear sequence of steps used in carrying out the given investigation.

Areas for students to improve include:

• stating some specific safety measures and linking the use of safety equipment to its function
• indicating the relationship between time and rate of a reaction; rate is the inverse of time, meaning that a reaction that takes less time for completion has a greater rate.

Question 24

In better responses, students were able to:

• clearly identify the relationship between the independent and the dependent variables in formulating a hypothesis (a)
• correctly use and apply the terms reliability, validity and accuracy in identifying issues with the given experimental method (b)
• relate the design of an investigation to its validity (c).

Areas for students to improve include:

• distinguishing between an experimental aim and a hypothesis (a)
• explaining the relationship between the two variables tested in an experimental method, rather than just describing it (b)
• evaluating an experimental method in terms of validity, for example, does the experiment measure what it is intended to measure? (c)

Question 25

In better responses, students were able to:

• draw a line of best fit (a)
• identify inferences from the data given (c)
• explain the difference between causation and correlation using a specific example (d).

Areas for students to improve include:

• using appropriate scales on axes so that a clear indication of trends within the data can be seen (a) and (b).

Question 26

In better responses, students were able to:

• describe the importance of repetition to enhancing reliability
• relate the limitations in van Helmont’s experiment to the need to control variables.

Areas for students to improve include:

• describing how improvements in experimental design, such as controlling or measuring variables, lead to enhanced validity rather than just stating improvements.

Question 27

In better responses, students were able to:

• identify  eucalyptus and tea tree oils by Aboriginal or Torres Strait Islander Peoples for medicinal purposes (a)
• outline the potential use of native Australian plants for medicinal purposes (b).

Question 28

In better responses, students were able to:

• demonstrate detailed knowledge of the halo effect, false advertising, bias and denial
• describe the impact of using celebrities smoking or vaping
• analyse the impact of paid researchers presenting biased and unreliable findings about smoking to the general public.

Areas for students to improve include:

• providing detailed examples of misrepresentation or suppression by the tobacco industry, rather than making generalised comments about smoking and lung cancer.

Question 29

In better responses, students were able to:

• clearly describe the need for the peer reviewer to possess specific credentials and/or expertise (a)
• describe specific, suitable examples of the peer review process, such as was conducted in the work of Marshall and Warren (b)
• describe the purpose of peer review in terms of a collaboration of ideas.

Areas for students to improve include:

• clearly linking the peer review to the advancement of science (a)
• providing specific examples of peer review (b).

Question 30

In better responses, students were able to:

• correctly name a river and dam (a)
• relate the positive and negative aspects of damming to society and the environment (b).

Areas for students to improve include:

• linking a specific dam project to the public image of science by considering the issues surrounding the project and how these relate to the application of science as seen by the wider community (b).

Question 31

In better responses, students were able to:

• identify reflection and refraction
• describe how reflection and refraction were applied to new technologies.

Question 32

In better responses, students were able to:

• provide a structured response  that included a named medical surgical device, linking the use of the device to improved human health.

Areas for students to improve include:

• describing the specific applications of the device rather than just identifying diagnostic tools or minimally invasive surgery.

Question 33

In better responses, students were able to:

• clearly link current ethical issues, such as animal testing, cloning or gene editing, to scientific research (a)
• link a protocol or ethical code of conduct with scientific research (b).

Areas for students to improve include:

• describing an established code of conduct in scientific research to specific ethical standards (b).

Question 34

In better responses, students were able to:

• detail the implications of scientific research on a range of areas such as social, ethical, political, economic and environmental areas.

Areas for students to improve include:

• providing examples to support their answer.