1. Year 9Science
Term 3 2013
The Infection Analogy
Due Date: Monday 2nd
of September 2013
Teacher: Ms Lawrence
Length:3-4 pages approximately
Task Description
Many disease-causing pathogens can survive on surfaces around us, waiting to be
picked up by a potential host. You are to examine sources of infectious diseases
around the school (eg. Sinks, tables, door handles) using nutrient agar in petri dishes
to grow them to a visible state.
You will write a scientific report detailing your results and giving a picture of possible
infection around the school. You will need to examine results from other students in
the class to get a picture of the school as a whole.
What will it look like?
(HINT: use this table as a checklist!)
Aim and
Hypothesis
What were you trying to test? What results did you think you would get? Be
specific!
Introduction (1/3 of a page) Background information. How do pathogens infect human
beings? How do we grow pathogens in the lab for study? What type of
pathogens can be grown in petri dishes? How can the risks of experimenting
with pathogens be controlled in experiments like this?
Materials and
Method
Materials may be listed in dot points.
Method is an accurate description of what you DID, written in passive past
tense voice and in a numbered format.
Results
(Observations
and Graphs)
- Observations of different types of organism found on petri dishes.
- Table of results from the class detailing types of organism and where
it was found.
- Graph showing types of organisms and how frequently they were
found around the school.
Discussion Explain which variables were controlled, changed and measured in
this experiment.
Describe the results/graphs.
Explain any significant findings.
Why do you think students and teachers at this school can be
relatively healthy with so many potential pathogens around?
List any sources of error.
Explain how these might be reduced.
Suggest ways to improve the experiment.
Conclusion A brief statement summarising your experiment, including whether or not
you achieved your aim.
Bibliography Any websites or books you looked at for additional information.

2. Marking Guide
By the end of Year 9, students explain chemical processes and natural radioactivity in terms of atoms and energy
transfers and describe examples of important chemical reactions. They describe models of energy transfer and apply
these to explain phenomena. They explain global features and events in terms of geological processes and
timescales. They analyse how biological systems function and respond to external changes with reference to
interdependencies, energy transfers and flows of matter. They describe social and technological factors that have
influenced scientific developments and predict how future applications of science and technology may affect people’s
lives.
Students design questions that can be investigated using a range of inquiry skills. They design methods that include
the control and accurate measurement of variables and systematic collection of data and describe how they
considered ethics and safety. They analyse trends in data, identify relationships between variables and reveal
inconsistencies in results. They analyse their methods and the quality of their data, and explain specific actions to
improve the quality of their evidence. They evaluate others’ methods and explanations from a scientific perspective
and use appropriate language and representations when communicating their findings and ideas to specific
audiences.
A B C
Achieving at year level.
D E
- Analyse how biological systems function and respond to external changes.
Investigated the presence of
microorganisms and identified
potential for infection from
them.
Investigated the presence of
microorganisms.
Has not investigated the presence
of microorganisms.
- Design methods that include the control and accurate measurement of variables.
- Systematic collection of data.
Considered how much data are
needed to produce reliable
measurements.
Applied specific skills for the
use of scientific instruments.
Explained the choice of
variables to be controlled,
changed and measured.
Applied specific skills for the
use of scientific instruments.
Has not explained the choice of
variables to be controlled,
changed and measured.
Has not applied specific skills for
the use of scientific instruments.
- Describe how they considered safety.
Describes the potential hazards
of biological materials used in
experimental investigations in
Introduction. Control measures
listed in Method and followed
during practical work.
Identifies the potential hazards
of biological materials used in
experimental investigations.
Potential hazards of biological
materials used in experimental
investigations not identified.
- Analyse trends in data, identify relationships between variables and reveal inconsistencies in results.
Relationships between variables
explored using tables and
graphs.
Described sample properties to
predict characteristics of the
larger population.
Presented data in tables and
graphical forms to carry out
analyses on data.
Analysed graphs for trends
and patterns.
Data not presented in tables or
graphical forms.
Graphs not analysed for trends
and patterns.
- Analyse their methods and the quality of their data
- Explain specific actions to improve the quality of their evidence.
Identified the strength of the
conclusion that can be inferred
from a particular data set.
Identified where human error
can influence the reliability of
data.
Explained specific actions to
improve the quality of the
evidence.
Identified gaps or weaknesses
in conclusions.
Considered how investigation
methods and equipment may
influence the reliability of
collected data.
Explained specific actions to
improve the quality of the
evidence.
No gaps or weaknesses identified
in conclusions.
Investigation methods and
equipment not considered in
terms of reliability of collected
data.
No specific actions to improve the
quality of the evidence explained.
- Use appropriate language and representations when communicating their findings and ideas to
specific audiences.
Evidence based arguments
constructed using results as
basis.
Results and ideas presented in
formal experimental report.
Secondary sources used to
validate findings.
Results and ideas presented
using a formal experimental
report.
Secondary sources used to
help explain scientific
concepts.
Results not presented using a
formal experimental report.
Secondary sources not referred to.