Inquiry: Lives of Fungi [Activity designed by Barbara Dorritie]

Grade level: 6-12, could be modified for lower grades

This activity uses an inquiry model for students to investigate fungal life cycles. It implements the elements of inquiry based science learning: students are allowed to examine materials, discuss what they already know, generate questions about what they would like to know, design experiments to test ideas, collect and analyze data, and present their findings. These activities were carried out with teachers over a series of five days, for approximately one hour each day. In practice, investigation over a longer period of days (e.g. ten) would be necessary, and more fruitful. The model can be adapted to fit time periods available, and can be used to investigate any topic in an inquiry-based manner.

Day 1: Students were given a period of time to make their own observations of the following: store-bought mushrooms, field collected mushrooms, exposure plates containing colonies of fungi (molds). Hand lens, dissecting microscopes and brightfield microscopes were available for their use. Instructions for making exposure plates are given below.

Following this, students were asked as a group "What do you know about fungi?" All answers were recorded on large pieces of newsprint until no more answers could be generated. Examples of "What we know about Fungi" were:

• Grows as fuzzy threads (hyphae)
• Can be good to eat
• Can be poisonous
• Are different shapes and colors
• There are 3 kinds- ascomycetes, basidiomycets and something else
• They have mycelium
• They can make beer and alcohol
• They grow from spores

A mystery object (which was a giant orange fungus collected from someoneâs lawn) was passed around for a Questioning Circle (see activity entitled Questioning Circle, below). Students addressed the object, and asked it questions. All questions were recorded on newsprint until no further questions were generated. Examples of "Questioning Circle" questions were:

• Why are you orange?
• Where did you come from?
• Is this just a small piece of you, or the whole thing?
• Do you have sex?
• Were you found under a tree?
• Are you edible?
• Are you one thing, or many things grown together?

Following the questioning circle, students were given a few more minutes to examine the collected and cultured fungi. They were given the assignment to come up with a question they wanted to investigate further and to find others to form a group (of 2 or 3) to work on the same question. Instructors consulted with students to generate testable questions.

Day 2: Students were asked to form groups with others interested in answering similar questions. After a few minutes of organization, they wrote their questions on newsprint, and posted the near their groups. Examples of questions for group investigation were:

• What is the green stuff?
• Do different flowers have different fungi?
• Do different media select for different fungi?
• Do fungi grow better in the light or dark?
• At what temperature do fungi grow best?

Students were made aware of materials and equipment available for their experiments. Each group consulted with instructors to determine what could be done with the materials at hand, to formalize plans for experimentation, and to revise experiments if necessary. Students were asked to record their questions and experimental plans in their journals. Time was given for experiments to be started.

Day 3 (48 hours later): Students were given time to continue their investigations, record results and observations, and to begin thinking about how to present their findings.

Day 4: Each group was given 5 minutes to present their results so far, the problems they encountered with their experiments, and ideas for how they would continue their investigations given more time.

Recipes

Potato Dextrose Agar ( Fisher Scientific number DF0013-15-8, 100g, $30.95)
If using premixed Potato Dextrose Agar (PDA), follow instructions on the container for mixing. Premixed and prepoured plates of PDA can also be purchased. PDA can also be "made from scratch".

Cut a large potato into 1” cubes and boil in about two cups of water. Boil until the potato is soft, and begins to fall apart. Mix 100 ml of this "potato infusion" with 400 ml of water in a flask. Add 10 g. glucose. Adjust pH to 5.6 using dilute hydrochloric acid and add 7.5 g agar. Autoclave for 15 minutes and pour into sterile plates.

Sabouraud Dextrose Agar (Fisher Scientific number DF0747-17-9, 100g, $20.40)
If using premixed Sabouraud Dextrose Agar (SDA) , follow instructions on the container for mixing. Premixed and prepoured SDA plates can also be purchased or made as follows:

Sabouraud Dextrose Agar
Glucose - 10 grams
Neopeptone - 5 grams
Agar - 7.5 grams
Water - 500ml
pH 6.8-7.0

Mix ingredients in a flask, autoclave for 15 minutes, and pour into sterile plates.

Tomato Juice Agar
250 ml tomato juice
250 ml water
15 grams of agar

Mix ingredients in a flask, and autoclave for 15 minutes. Pour into sterile petri plates. Note: This media contains twice the typical amount of agar. Tomato juice is acidic, and tends to break down agar, leading to mushy media. Adding more agar prevents this problem.

Bread Agar
Hot dog bun (or other bread), shredded into small pieces
500 ml water
7.5 g agar

Blend bread and water in a blender until smooth. Pour into flask and add agar.
Autoclave mixture for 15 min. and pour into plates. Will make about 20 plates

Exposure Plates:

Place sterile Potato Dextrose Agar plates or Sabouraud Dextrose Agar Plates on a flat surface, either inside a room or outside, and open lid of plate for approximately 20 minutes. Close plate and incubate upside down at room temperature for 4-5 days. Lengths of exposure can be varied and compared. Additionally, pieces of bark, mulch, or leaves can be pressed onto the surface of the plate for a few seconds, and then removed. Incubate plates as above.

Questioning Circle (activity provided by Barbara Dorritie)

Grade level: all

Materials needed:
Newsprint
Tape
Markers
Overhead of questioning circle directions (optional)
Mystery object in a dish or plastic bag

Background: This activity is part of a series of activities that would be used as an Îinvitation to inquiryâ. It could be used to introduce any subject. We would first ask students "What do you know about X?" After writing down all answers on pieces of newsprint posted around the room, students would then have an opportunity to make some observations of materials related to the unit. Following this, we had students participate in a questioning circle, using a particular Îmystery objectâ. We then used the results of the questioning circle to direct students into working on experimentally testable questions in groups. The rules of questioning are given below.

Questioning Activity:

This activity works well as an opening to a unit or lesson. It helps students practice observation, questioning and listening skills.

Directions: Students sit in a circle and an object is passed around. Each person, in turn, examines the object, asks it a question and passes the object to the next person. Questions are recorded.

Guidelines:

You may not ask "What is it?"
You may not repeat a question someone else has already asked
You may pass (and not ask a question) in one round, but not in the next
Questioning rounds continue until there are no more ideas

Extensions:

Categorize the questions as to how they might be answered (i.e., by experimentation, research (asking an expert, reading books, looking on the internet] or funny questions); as a class or in small groups begin the research
Create a learning center in the classroom with the object, the list of questions and materials students might need to investigate the questions
Encourage students to bring in objects from home and initiate their own questioning circles