Biology 11–12 · Year 12
Koch's postulates with blue mould rot of apples (Penicillium expansum)
Module 7: Infectious Disease (Causes of Infectious Disease: Koch's postulates)
Teacher-led demonstration
A teacher carries out this activity as a demonstration. Its materials, steps, variables, misconceptions and sources are not published on the open web, and neither is any result, control or note that states a number or an amount: tutors and administrators read them on the learning platform, with the safety card first. The idea, the hazards and the curriculum references are below.
Open the procedure on the learning platform (tutor or administrator sign-in)
School laboratory, not for home
In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
The idea
A microbe is shown to cause a disease only when it is isolated from the diseased host, grown in pure culture, used to reproduce the same disease in a healthy host, and isolated again.
Safety card
Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
Hazards
- Sporulating mould releases spores that can trigger allergy or asthma
- Scalpel and Bunsen flame
- Ethanol near a flame
Controls
- Only staff trained in microbiology transfer the fungus between fruit and agar, since RiskAssess advises against sub-culturing without that training; learners observe sealed plates and closed containers
- Face masks for anyone with an allergy, as the SAPS notes advise; containers stay closed during measurement
- Ethanol capped and away from the flame; all cultures and fruit sterilised by autoclave or pressure cooker before disposal
Note
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
What you should see
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Biology Stage 6 Syllabus (2017), current: Year 11 taught to the end of 2026 and Year 12 to Term 3 2027BIO12-14BIO11/12-2BIO11/12-3
- Biology 11–12 Syllabus (2025), Year 12 focus area Diseases; new syllabus not yet taught: Year 11 from Term 1 2027, Year 12 from Term 4 2027BI-12-02
- Biology 11–12 Syllabus (2025), Year 12 Working scientifically; new syllabus not yet taught: Year 11 from Term 1 2027, Year 12 from Term 4 2027BI-12WS-02BI-12WS-03BI-12WS-05
- Australian Curriculum v9No Australian Curriculum v9 code is listed.