Name: _________________________
CLASS: _______
Background
Centuries ago people treated infections in a rather curious way. They often placed
decaying breads, cheeses, and fruits such as oranges on the infection. Although the
people did not have a scientific reason to do this, every once in a while the infection was
cured. What these people did not know was that the cure was due to a type of fungus,
called mould, which grows on some foods.
In 1928, the Scottish scientist, Sir Alexander Fleming found out why this treatment
worked. Fleming discovered that a substance produced by the blue-green mold
Penicillium could kill certain bacteria that caused infections. Fleming named the
substance Penicillin. Since that time Penicillin, an antibiotic, has saved millions of lives.
Have you ever seen mould growing on bread? Bread mould looks like tiny fluffs of
cotton. The fluffs are groups of long hyphae that grow over the surface of bread. Shorter
hyphae grow down into the bread and resemble tiny roots. The shorter hyphae release
enzymes that break down chemicals in the bread. The broken-down chemicals are
foods for the mould and are absorbed by the hyphae. The tiny black spheres on bread
mould are spore cases, which produce spores. The spores are carried from one place
to another through the air. When the spores land on food, they begin to develop into a
new mould.
Adapted from: http://www.mrpscience.com/Overview&SciMeth/Handouts/Lab-BreadMold.pdf
When writing your project, follow the structure below including front cover page.
Purpose: What affects the growth of bread mold?
Hypothesis: Predict what will happen as a result of your changing one variable in the procedure
below. Will bread mould growth (when compared to the class control) be inhibited, promoted, or not
affected?
Materials:
Plastic Container, 1 Slice White Bread (exposed to air for 8 hours), Tape, Graduated Cylinder, 10 ml
Water, Other materials as used (record what & how much you used)
Procedure/Method:
Control
1. Place one slice of white bread in a plastic container
2. Moisten bread with 10 mls water.
3. Seal container with tape and place in a dark cabinet (at room temperature).
Experimental
4. Follow the same procedure as for the control except [change one variable so that you can see how it
affects the growth of mould.] Write what you did as this part of step 4.
5. Observe both the control and experimental bread every day for 1 week.
6. Record your observations and take pictures. Be specific and descriptive!
Observations:
1. Make your observations in your lab book every day. Observations should be placed in a table format.
2. Beware of drawings! They are only useful if they are detailed enough to be understood by someone
who has not actually done the lab.
Analysis:
1. What was the independent variable in your experiment?
2. What was the dependent variable in your experiment?
3. What were two controlled variables in your experiment?
4. What was the control in this experiment & how was it used?
5. Why do you think you got the results you did?
6. Compare your results with the results of one other group.
Conclusion:
Was your hypothesis supported or not supported by your data? Why?
CATEGORY
Variables
Hypothesis Development
Description of Procedure
Diagrams
Conclusion/Summary
TOTAL
COMMENTS
4
Identified and
clearly defined
which variables
were going to be
changed
(independent
variables) and
which were going
to be measured
(dependent
variables)
Hypothesis wellsubstantiated.
Procedures were
outlined in a stepby-step fashion
that could be
followed by
anyone without
additional
explanations.
Provided an
accurate scientific,
easy-to-follow
diagram with
labels to illustrate
the procedure or
the process being
studied.
Pupil provided a
detailed
conclusion clearly
based on the data
and related to
previous research
findings and the
hypothesis
statement(s).
3
Identified which
variables were
going to be
changed
(independent
variables) and
which were going
to be measured
(dependent
variables). Some
feedback was
needed to clearly
define the
variables.
Hypothesis
somewhat
substantiated.
Procedures were
outlined in a stepby-step fashion
that could be
followed by
anyone without
additional
explanations.
Some clarification
needed.
Provided an
accurate diagram
with labels to
illustrate the
procedure or the
process being
studied.
Provided a
somewhat
detailed
conclusion clearly
based on the data
and related to the
hypothesis
statement(s).
2
Identified only
one variable but
not clearly
defined
1
No variables
identified at all.
Hypothesis not
clear.
No Hypothesis
Procedures were
outlined in a stepby-step fashion,
but had 1 or 2
gaps that require
explanation.
Procedures that
were outlined
were seriously
incomplete or not
sequential.
Provided an
easy-to-follow
diagram with
labels to illustrate
the procedure or
process, but one
key step was left
out.
Pupil provided a
conclusion with
some reference
to the data and
the hypothesis
statement(s).
Did not provide a
diagram OR the
diagram was
quite incomplete.
No conclusion
was apparent OR
important details
were overlooked.
20