Science Inquiry Skills - Human Biology Notes

Science Inquiry Skills

  • Year 11 ATAR Human Biology
  • Mrs. Peace

Holidays

  • Discussion about summer holidays and highlights.

Course Outline

  • Resources mentioned:
    • Curriculum documents
    • WACE handbook
    • Compass
    • Nelson Human Perspectives

WACE Requirements

  • Complete a minimum of 20 units.
  • Achieve at least 14 C grades or higher.
  • At least 6 C grades in year 12.
  • Demonstrate minimum standards in literacy and numeracy.

Reflection & Goals

  • Consider the challenges of ATAR.
  • Define goals and reasons for achieving them.

Home Study

  • Weekly assignments due on Monday.
  • Chapter reading and review questions.
  • Completing pages in booklets.

Syllabus Points

  • The human body is comprised of cells, tissues, and organs within complex systems that work together to maintain life.
  • Cell organelles maintain life processes and require the input of materials and the removal of wastes to support efficient functioning of the cell.
  • Science Inquiry Skills (SIS) 1 and SIS 2 are relevant.

What is Human Biology?

  • Scientific study of humans as individuals and populations.
  • Study of interaction between humans and their environment.
  • Knowledge builds upon discoveries made by each generation.
  • Utilises a wide range of fields of study to develop an in-depth knowledge of humans.

The Scientific Method

  • A process of investigation to gain scientific knowledge.
  • Generally follows a pattern known as the scientific method.

Scientific Method (cont.)

  • If the hypothesis is disproved.
  • If the hypothesis is supported.

Scientific Method - Identifying a Problem

  • Scientific investigation begins with a problem.
  • Curiosity about why and how things happen.
  • Aim: Describes what you are trying to achieve in the experiment.
    • 1-2 sentences "To determine if…"

Scientific Method - Collecting Information

  • Having defined the problem, the scientist begins collecting information.

Identifying Variables

  • A variable is any factor that may change during an experiment.
    • Independent variable: The factor deliberately changed.
    • Dependent variable: The factor that changes in response to the independent variable. We measure this variable.
    • Controlled variables: Factors kept the same to ensure the experiment is valid.

Developing a Hypothesis

  • Hypothesis: a statement of the expected relationship between the independent and dependent variable that can be tested.
  • A hypothesis requires investigation to collect evidence that will support it, and therefore must be testable.
  • A good hypothesis:
    • Is a definite statement, not a question.
    • Is short.
    • Has a single idea that can be tested.
    • Usually links the independent and dependent variables.
  • A hypothesis should state what you think the relationship is between the variables.

Activity: Pick the Hypothesis

  • Examples:
    • "If students study, average test results will increase."
    • "If student time studying is increased, average test results will increase."
    • "Studying more will make test results better."

Practice Exam Question

  • Scenario: Tegan gave 20 rats different amounts of food to see which could get through a maze the quickest.
    • Independent Variable: Amount of food.
    • Dependent Variable: Time to complete the maze.
    • Controlled Variables: (To be specified).
    • Hypothesis: (To be formulated).

Home Study (cont.)

  • Read Chapter 1.2 of the textbook.
  • Answer 1.2 chapter review questions (page 13).
  • Due on Monday, February 10th.

Do Now Activity

  • Norman's paper airplane experiment:
    • Independent Variable: Number of paperclips.
    • Dependent Variable: Distance the airplane flies.
    • Controlled Variables: (To be specified).
    • Hypothesis: (To be formulated).
  • Diana's tin can experiment:
    • Independent Variable: Color of the tin cans.
    • Dependent Variable: Temperature of the cans.
    • Controlled Variables: (To be specified).
    • Hypothesis: (To be formulated).

Materials & Method

  • Materials:
    • List materials.
    • Must include quantities and UNITS.
  • Method:
    • Detailed and repeatable.
    • Could someone else follow your method?
    • Include everything you did, including pre-trials and trials.

Results Table

  • Measurements and observations are easier to read and analyze if displayed in a table.
  • Tables require:
    • Headings with units.
    • Results tables NEED a title with IV and DV.
    • Groups relevant data.
    • Averages trials.
  • Generally, the independent variable is on the left and the dependent at the top.
  • Should include an average column.

Sample Table

  • Structure:
    • Title: The Effect of the independent variable on the dependent variable.
    • Column for independent variable (label with units).
    • Column(s) for dependent variable (label with units, multiple trials).
    • Column for derived quantity (e.g., average of trials, label with units).

Graphing Data

  • Graphs must include:
    • A title that summarizes the relationship between the variables.
    • Y-axis label and units (dependent variable).
    • X-axis label and units (independent variable).
    • Use a scale with equal intervals of units on each axis.
    • Appropriate graph type selected.
    • If you calculated averages, these are the values you need to plot on your graph.

Types of Graphs

  • Line graphs:
    • Used when continuous data is being represented (e.g., length, mass, time, pH, and volume).
    • When there is a trend, a line of best fit is drawn (straight line or smooth curve).
  • Bar or column graphs:
    • Used to graph discrete data.
    • Data is represented by rectangles of equal width with spaces between them.
    • The length of each rectangle indicates the quantity.
    • Rectangles are drawn horizontally for a bar graph and vertically for a column graph.

Quick Check - Which Graph Type?

  • Examples for selecting the appropriate graph type:
    • Height of a child recorded every year from birth to year 6.
    • Number of pens each student in Human Biology has.
    • Amount of vitamin C in different fruit juice brands.
    • Weight of a dog recorded monthly.
    • Weight of 10 different babies.

Sample Exam Question

  • Data Table: Activity Level vs. Heart Rate (Teenagers and Adults).
  • Task:
    • Create a graph to display the data.
    • Answer analysis questions:
      • Describe the trend in heart rate.
      • Suggest a physiological reason for heart rate differences.

Trends of Data & Graph

  • State the patterns you see in the graph; use number values.
  • Did the independent variable have an effect on the dependent variable?
  • No pattern? State the ranking of the dependent variables related to the hypothesis.
  • If you can, calculate the percentage change.

Conclusion

  • Relate trend back to the hypothesis.
  • Does this support or reject your hypothesis?
  • You MUST explain why.

Validity

  • Evaluating the experiment.
  • Scientists should reflect on the results and the method.
  • Validity: A valid method will fairly test the hypothesis so that the only factor that affects the results is the independent variable.
  • Does my experiment test what it is meant to?
  • A test is valid if it measures what it claims to measure.
  • Validity refers to experimental method and how appropriate it is in addressing the aim of the experiment.
  • Comment on the addition of any controlled variables that could have eliminated the sources of error.

Accuracy

  • The accuracy of the results refers to how correct or true the measurements are.
  • Types of error:
    • Human error: A mistake (e.g., incorrectly reading a scale). Avoidable with care and checking.
    • Random errors: Unpredictable errors that can occur in all experiments. Reduced by taking several measurements and averaging them.
    • Systematic errors: Occur due to the experiment's design or equipment problems. Requires changing the experimental procedure or equipment.

Reliability

  • Reliability is how close repeated values are to each other (consistency).
  • Example: Arrows landing closely together, even if not on the bullseye, demonstrate good reliability.
  • Reliable results are identified by conducting multiple trials and comparing the measurements.

How to Improve Reliability

  • Reliability can relate to single measurements or the entire experiment.

Ethics

  • Ethics: A set of moral principles or values.
  • Ethical behavior conforms to those principles or values.
  • Five principles of an ethically sound investigation:
    1. Voluntary participation: No pressure to participate.
    2. Informed consent: Participants fully informed; written consent obtained.
    3. Risk of harm: Possibility of harm minimized and assessed.
    4. Confidentiality: Identities of participants not revealed.
    5. Anonymity: Participants remain anonymous, even to researchers.

Placebos

  • Placebos are used in research into the effectiveness of medical treatments.
  • A placebo is an inactive substance that looks like the real medication.
  • Experimental group takes the drug; the control group takes the placebo.
  • Placebo effect: Patients given a placebo often show improvement.
  • Blind experiments: Subjects don't know if they're receiving the placebo or treatment.
  • Double-blind experiment: Neither the researcher nor the subjects know who is receiving the treatment or the placebo.

Recap Questions

  • State the 5 principles that must be satisfied for an ethically sound investigation.

Recap Questions

  • Describe a double-blind experiment.

Practice

  • Work through the application activities on pages 8-12 of your booklet.