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B4.2.6—Saprotrophic nutrition in some fungi and bacteria


Here are experiments our science specialists have selected to support this IB* topic.

Evolution of Cellobiase in Fungi

Experiment #20 from Investigating Biology through Inquiry

In this Preliminary Activity, you will (1) produce a button mushroom extract, (2) react this cellobiase-containing extract with substrate, (3) collect samples after 1, 2, 3, 4, and 6 minutes of reaction, (4) use a spectrophotometer to measure the absorbances of the colored samples, (5) plot a graph of absorbance vs. time, and (6) use the graph to determine the rate of the cellobiase catalyzed reaction.

After completing the Preliminary Activity, you will first use reference sources to find out more about mushrooms, cellobiase activity, and the evolution and ecology of mushrooms before you choose and investigate a researchable question dealing with cellobiase and the evolution of mushrooms. Some topics to consider in your reference search are:

  • cellulose
  • cellobiose
  • cellobiase
  • basidomycota
  • ascomycota
  • mycorhizal
  • ecology
  • evolution

Educational Standard
International Baccalaureate (IB) 2025
B Form and function
Level of organization
4 Ecosystems
B4.2 Ecological niches
Standard level and higher level

* The IB Diploma Program is an official program of the International Baccalaureate Organization (IBO) which authorizes schools to offer it. The material available here has been developed independently of the IBO and is not endorsed by it.