HSC Sample Exam

HSC style Questions and sample responce

Question 5 (15 marks) 

Penicillin was discovered in London in September of 1928. Doctor Alexander Fleming was a bacteriologist who worked at St Mary’s Hospital, London. It is reported that after he returned from a summer vacation in Scotland he found a messy lab bench and a good deal more. Upon examining some colonies of Staphylococcus aureus, Fleming noted that a mould called Penicillium notatum had contaminated his Petri dishes. After carefully placing the dishes under his microscope, he was amazed to find that the mould prevented the normal growth of the staphylococci. It took Fleming a few more weeks to grow enough of the mould so that he was able to confirm his findings. His conclusions turned out to be phenomenal: there was some factor in the Penicillium mould that not only inhibited the growth of the bacteria but, more important, might be harnessed to combat infectious diseases. Reproduced with the permission of Dr Howard Markel. (https://www.pbs.org/newshour/health/the-real-story-behind-the-worlds-first-antibiotic

To what extent do discoveries in science occur as a result of planned experiments? In your answer include a reference to the stimulus provided and your Scientific Research Project.

Sample 1

The process of conceiving a new idea is a discovery this is through the human mind gaining a new insight to explain or predict phenomena, however, planned experiments validate the discovery in order for it to hold up to the rigour of science. Both Dr Fleming and my own scientific research was characterised by the “eureka moment” whereby a new discovery was conceived. However, for this discovery to be accepted by science it had to pass the rigour of scientific testing through a valid experiment which had to be planned. This process of conceiving and validating a discovery is cyclical and allows science to progress. Therefore, scientific discovery is not a result of planned experimentation, however, the acceptance of the discovery into science requires it to be validated through a planned investigation.

A discovery can be formulated through preexisting science or directly observing a phenomenon. For my own research, …. Similarly, Dr Flemming devised his discovery of penicillin killing bacteria – something that was not previously known to science, however, he did it through directly observing something which had not been previously recorded. It was by accident “Penicillium notatum had contaminated his Petri dishes” but the act of observing that penicillium could kill Staphylococcus aureus resulted in his eureka moment – he also identified that this discovery could be applied to treat patients.

Both my report and Dr Fleming used the discovery to make a hypothesis in order to validate the discover through designing and carrying out a planned experiment. My hypothesis… was tested through a planned experiment repeated multiple times with the same results reoccurring to ensure reliability. Through modelling the two treatments than using a paired one tail t-test I could rigorously demonstrate it as a more effective treatment then …. Similarly, Dr Fleming’s cultured more plates in order to ensure reliability in his observations so he could carry out planned experimentation in order “to confirm his findings”. The act of confirming our findings allowed our discoveries that we devised to be validated in order to become apart of science.

In making our discoveries we had to provide reasoning – which required a falsifiable hypothesis – and through rigorous testing, we were unable to disprove this hypothesis. The cyclical cycle of science is characterised by facts -> hypothesis -> theory -> prediction this, in turn, allows more facts to be discovered repeating the process. Hence future experimentation may disprove our explanation of our discoveries however the observation(fact) remains true. Therefore, we conceived facts and assigned hypothesis’ to explain the facts and used planned experiments to test our hypothesis, not the fact. Hence what we associate the eureka moment with is the discovery of facts. The planned experimentation is then used to test not the hypothesis which is used to explain the facts and in the testing period, new facts may be discovered.

Therefore, a discovery must have a tested hypothesis in order for it to be inducted into science. However, the discovery is what the scientist observes which was previously unknown. The planned experimentation is used to test the hypothesis to explain the discovery which in turn allows for new discoveries to be made.

Sample 2

The majority of discoveries in science are usually unexpected results through both unplanned or planned experimentation, however, it is through planned experimentations that a discovery can be verified, passing the rigour of scientific testing. 

My research project was an exploratory style project, by nature of this study the discoveries made were unexpected, however, they arose through planned investigation. Through comparing the effectiveness of a … – my proposed treatment was discovered to be more effective. The planned investigation had a control (no treatment), an independent variable (Type of treatment) and a dependent variable (tumour volume) hence making it a controlled experiment. 

I developed a model for …, verifying it against a valid model for … growth. This increased the validity of my study – this was one of my major milestones throughout the year. I then randomly generated numerous numbers for the initial volume of the correctional cancer tumor, this increases the reliability of my results since I used multiple samples and found my results to be repeated in the majority of the samples. Throughout my project, I was concurrently conducting a literature review since science is an ever-changing field. 

Likewise, Alexander Fleming conducted an exploratory style project, however, his initial discovery of the antibacterial properties of the penicillin fungus was an accidental “fluke”. Hence making his initial project unplanned, these stories are more memorable then planned experiments hence making it appear that the majority of science occurs due to unplanned experiments – this is not the case. Fleming still had to spend a “few more weeks” to culture more microbes and conduct planned experiments to determine and validate the results of his initial unplanned experiment. Discovery is only accepted in science once it has attempted to be disproved and passed the tests hence the planned experimentation is pivotal to a discovery.

Epistemology is the philosophical study of science which questions “how do we get knowledge?” From an empirical viewpoint, new knowledge can be gained through the senses hence suggesting we need to discover what we don’t know i.e unplanned investigations, such as Fleming’s to discover previously unknown phenomena’s. This also applies to observations such as Issac Newton observing that an apple and the moon both fall towards the earth. In contrast, rationalism can draw upon unknown facts to establish a new conclusion’s hence making new discoveries in science. In my project, I conducted a literature review which drew upon previous generalized rules. These were: …; …. Hence I used deductive reasoning to propose …. Hence empiricism can arrive at new discoveries in science without planned investigations and through observing the environment, however, rationalism relies on previous knowledge to make new conclusions. Both of these ways of knowing related to epistemology rely on planned investigations to verify the conclusion.

Therefore, Discoveries in science can arise through unplanned and planned experiments, however, “lucky” results are more memorable in science. In order for the discovery to be accepted in the scientific community, it must be tested with planned experiments attempting to disprove it.

Scientists use the knowledge obtained from large datasets in order to produce models, of which climate change is an example. 

  1. Evaluate the use of predictive and descriptive data modelling techniques used in contemporary science. Use appropriate examples in your response. [6 marks]
  2. With regard to data modelling, analyse at least TWO current influences which impact upon the direction of scientific research and thinking. [5 marks]
  3. My project was a predictive data modelling technique which allowed me to … and contrast this to data gained through descriptive data modelling for the effectiveness of …. Descriptive data allowed for the analysis of previously known phenomena hence providing a real insight into the volume of cancer as time progresses. Whereas, predictive modelling allowed me to forecast the effectiveness of an untested treatment. Hence the effectiveness of treatment could be approximated before more time and money is put into it. Predictive modelling is therefore important in pharmaceutical companies, however, descriptive modelling is vital to validate the predictive model so the effectiveness of the treatment is known. This is because predictive modelling can not incorporate all the factors (e.g …) hence limiting the validity of its predictions.

Therefore, a predictive model is usually used as the precursor to a descriptive model since it is cheaper and more time effective. However, the results of a descriptive model must be used to validate the results since the predictive model is limited in that it can’t always incorporate all the factors.

  1. Political opinions regarding climate change being an important issue for current society has resulted in an increase in funding for research regarding this topic hence increasing the time and energy the scientific community is spending with regards to this. The model of the earth acting as a black body is a key idea to explain the dangers of an increasing CH4 (g) and other fossil fuels since they retain heat longer, therefore, the earth is emitting as much infrared radiation as it once was. This has lead to predictive modelling demonstrating this can cause the icing of the poles hence increasing sea levels to demonstrate the government’s investment is going towards an important cause. Additionally, economic factors favour scientific research with a clear ability to be applied to generate money. Research into and the development of transgenic organisms such as BT cotton which has the bacteria thuringenisis gene in it making it insect resistant was favoured financially due to it increasing profit since farmers with this crop didn’t need to use insecticide.

Testing hypotheses and theories is at the core of the process of science. Any aspect of the natural world could be explained in many different ways. It is the job of science to collect all those plausible explanations and to use scientific testing to filter through them, retaining ideas that are supported by the evidence and discarding the others. Ideas are supported when data matches expected observations and is contradicted when they do not match. As our ability to collect data improves, so does our ability to explain the world around us.

Analyse the impact of new data on established scientific ideas. 

In your response, make reference to ONE or MORE of the following:

  • gravitational waves in general relativity
  • mechanisms of disease transmission and control 
  • prediction of natural disasters 
  • effects of chemical pollutants on climate 

AND include your scientific research project and how your findings could impact future research studies15 marks

Before general relativity (gr) space and time were thought to be absolutes since Newton developed gravity whereby there was a central reference frame. Einsteins thought experiments created a paradigm shift through his new theory of gr which explained gravity through the curvature of space and time telling objects how to behave and the objects tell space and time how to curve. Recent refinements in atomic clocks accuracy have allowed to data to be developed to test gr by demonstrating time dilation and altitude hence supporting Einstein’s gr.

My own report created a paradigm shift in ….

Therefore, he concluded …

The above two examples demonstrate the ever-changing nature of science whereby new research leads to new hypothesis’ which in these being tested hence generating new discoveries and the cycle repeats. When hypothesis is combined together a theory is created which can be based on certain postulates. However, new scientific research buids upon previous research as my report did combining research from fundamental studies of the …. Hence future research could investigate my preemptive modelling through a mice model and generate descriptive data to analysis.

Occams razor then refines theory’s to apply the simplest and most accurate representation of facts. The mechanisms of disease transmission and control for cholera, a bacterial infection from Vibrio cholera which is water-born, has progressed throughout time. John Snow performed the first epidemiology study to link cholera outbreaks to a water well in London and research building upon this idea formulated the theory that it was caused by microbes hence allowing preventative methods such as water treatment and antibiotics to treat ill patients. However, African tribes linked cholera to God’s rath and explained it through it is God’s way to make people repent. Occum’s razor, however, favours the former explanation since it is simpler and has more evidence supporting it. Hence future research will build upon the ideas of cholera being caused by vibrio cholera.

Explain why a literature review is not just important at the start of report writing but all throughout (3 marks)

Science is an ever-growing field with new developments occurring every day hence a literature review must be conducted before and during a report, since new discoveries could occur hence making your work obsolete or outdated if you are not aware of what others have said. For example … Hence his own report incorrectly stated that ….

Using the stimulus, discuss the following statement: 

“Correlation and causation are the same”   (3 marks)

The above statement is flawed since causation can only be identified when other variables can be ruled out and the connection is logical. Whilst there appears to be a strong correlation between margarine consumption and divorce rates this doesn’t mean that one causes the other since this is illogical and other variables must be ruled out hence correlation results in causation – they are not the same. The idea that divorse is correlated to margarine consumption is spuriousness hence.

Read the following article, watch the video,  and answer the questions below. 

  1. Using the stimulus and a further example evaluate the contribution of cultural observational knowledge to modern scientific knowledge.  [6 marks]

Modern scientific knowledge is usually formed by the foundational pillars of cultural observational knowledge. Aboriginal people were capable of observing variable stars, something modern science could only do within the past 200 years. Hence this cultural knowledge didn’t help modern knowledge since we had to discover this astronomical phenomena. However, Aboriginal people’s knowledge of yellow beans and chemical equilibrium concepts for leaching phytohemagglutinin which apply Le Chatlier’s Principles so equilibrium is never meet since the products is constantly being removed. This tault modern science about the importance of not contaminating one’s own water supply, like the Aboriginal people, so we can better manage our own resources. Hence, Aboriginal knowledge predated current knowledge, however, we must merge the two pools of knowledge as we did for resource management as opposed to comparing the two as we did for variable stars.

  1. How does the process of discovery used by Aboriginal cultures, like indigenous astronomy, compare to modern scientific methodologies. [5 marks]

Science is fundamentally observing our surroundings and generating and testing hypotheses to explain what we observe. As modern science does for developing new treatments for disease – testing them upon patients e.g cisplatin trials to determine its effectiveness for treating colorectal cancer. Likewise, Aboriginal cultures tested there treatment processes for cicad leaching through feeding the cicad bread to to the elders and monitoring them for their response. This process of trial and error is the same as pharmacutical companies after it paces animal testing. However, Aboriginal people’s story of land formation was explained through the dreaming – this significant cultural religion was not tested through rigorous scientific testing as modern science is. For example, the theory of plate tectonics has been validated through satellite imaging detecting shifts in the location of planets and the magnetic direction of the poles being in different directions according to rocks depending upon when they were setting. Hence, their process of discovery remains the same whilst their testing of ideas differed. 

Marking Criteria? (9 marks)

  • Language of judgement/opinion/evaluation (significant, important)
  • Identify contributions of each culture x3
  • Cultural observational knowledge – link to the development of science using the language of explanation (cause and effect)
  • Links to historical times and the influences of those times (context)
  • Specific examples support your argument
  • Logical flow of argument…show planning – paragraphs

Explain: Inductive reasoning, deductive reasoning, Empiricism, Parsimony/Occam’s razorConfirmation bias, theory-dependence

Evaluate contributions of at least 3 different cultures to the development of science from 49000 BCE to 1500 CE  9 mark

The progress of science has been shaped by scientific thinking which has been greatly influenced by cultures including the Aboriginal and ancient Egyptian and Ancient Greek cultures.

During the 49000 BCE – 1700 AD, the Aboriginal culture amassed a large body of knowledge which made possible numerous culturally significant events which aided in survival. The Aboriginals influenced the nature of how we apply our scientific knowledge. For example, the process of leaching the cycad seed removes the water-soluble neurotoxin – an application of scientific knowledge which was created through inquiry, careful observation and refinement. Using the Aboriginal elders as their test subjects – they varied the process used to prepare the cycad seed (how much the diced it, how long it was in the slow-moving stream). Therefore, allowing them to determine whether the process worked (the vitals of the elders were the dependent variable). This application of science was influenced by their need for new sources of food to minimise their impact on the environment. Similarly, they moved around throughout the year to minimise their impact – this required scientific understanding of the stars and how they move with respect to the sun each season hence allowing them to use stellar navigation to also help the environment. Thus, Aboriginal people’s intrinsic connection to the land allowed them to develop mechanisms to help the environment by applying their scientific understanding hence allowing scientific knowledge to be increased. This influenced us to also apply our scientific knowledge in order to help the environment and society through technology which also drives our scientific understanding.

During 3000 BCE – 300 AD, the Egyptian culture hailed a God of science (Thoth) hence their scientific work acted as a means to praise the God’s making possible expensive developments, such as enormous irrigation system for agriculture from the Nyle, and the ability to pass on knowledge. The use of papyrus paper allowed for scientific knowledge to not only be passed onto future generations with greater validity and reliability of the written word since it’s not relying on human memory. This is mirrored in modern science in that everything we do is recorded in an ongoing log book so we don’t need to rely on our memory. Furthermore, the use of ship sails and sailing perpendicular to the wind drew on principles of aerodynamics and force vectors. The application of scientific knowledge to be applied to transport has acted as a source of financial support to facilitate research making our scientific endeavours possible. Additionally, the use of ships allowed for the exploration of the world precipitating the merging of cultural knowledge to develop science. 

Around 800 AD, ancient Greek culture developed our understanding of the fundamentals of science through careful observations of the environment – they very rarely conducted experiment’s, they drew their knowledge through thinking. Aristotle proposed a method of reasoning – deductive reasoning – which allows us to draw a specific conclusion from a generalised understanding. This is the cornerstone of modern scientific inquiry which is used to create hypotheses hence greatly influencing the process’ used for modern scientific inquiry. Additionally, our understanding of simple machines and mechanical advantage were influenced by the ancient Greek knowledge of . Archimedes proposed his “Archimedes spiral” which allowed for the development of the screw hence allowing instruments to be built to be used in scientific investigations. Therefore, the Greek culture provided modern science with the fundamental philosophic principles and tools for modern experimentation allowing scientific knowledge to grow.

Therefore, cultural knowledge from ancient Greek, Egyptian and Aboriginal cultures act as a cornerstone of modern scientific understanding and inquiry- making it possible to conduct scientific investigations through facilitating the development of scientific instruments, a fundamental philosophical understanding of science and apply our knowledge to aid in the world. Namely; the Aboriginal people’s ability to apply their scientific concepts to help people and the land hence we too apply our understanding to drive technological development to improve society and the environment, the Greek cultures philosophical developments so we can plan and conduct experiments with an underlying philosophical understanding and drawing upon the Egyptians method for preserving and passing down scientific knowledge.