Introduction:
Fungi are found all around us. Examples include baker’s yeast, mushrooms and common bread mold. Mold grows from spores that can be found almost anywhere. In Rhizopus, the body of the fungus is called the Mycelium (myketos is the Greek word for fungus) and consists of non-sexually reproducing cells in strands called Hyphae.
Specialized areas of Hyphae invade starchy foods such as bread and secrete digestive enzymes. Yeast, is a unicellular fungus that has a single nucleus and reproduces either asexually by budding and transverse division or sexually through spore formation.
Each bud that separates can grow into new cell, and some together to form colonies. Generally yeast cells are larger than bacteria, vary considerably in size, and are commonly spherical to egg shaped. They lack flagella and cilia but posses most other eukaryotic organelles.
Fungal cell walls resemble plant cell walls architecturally but not chemically. Most fungi have cell wall contain of chitin instead of cellulose although a few may have composition of cellulose.
Understanding the structure and composition of fungal cell walls are of importance because it has significant biotechnological purposes and the chemical nature of the cell wall is important in classifying fungi for research and industrial purposes.
Mold spores are so small they can’t be seen with the naked eye, except maybe as a puff of dust. Spores travel through the air, on animals, on human skin and clothes, and even get washed to new places by rain and streams. Mold spores are all around us, but they remain dormant until they land in a place that has the right conditions for growth.
Question:
If fungi spores are so small that they are almost invisible and they are all around us, why don’t we see mold everywhere?
Hypothesis:
The hypothesis is what you propose to answer the question. Usually it uses part of the question and can be stated in the following structure:
If (independent variable) _________ (characteristic)……., then ____________ (dependent variable – conclusion)….
Example hypothesis: If mold is everywhere and it’s microscopic, then, I’m being consumed by mold right now.
Objective:
Observe, identify and explain the parts of the fungi to understand how they reproduce.
Materials – Part 1:
- Microscope
- Glass slides
- Pliers
- Moldy Bread
Materials – Part 2:
- 2 plastic bags
- 1 slice of bread
- Permanent marker or pen
- Water mister bottle
- Paper towel
Procedures – Part 1:
- Observe the moldy bread in the microscope and make a very detailed drawing of it.
Procedures – Part 2:
- Using the clean plier, take a piece of bread from the package 1 and rapidly place it into the plastic bag. Spray some water on it and seal it quickly.
- Using your hand, grab a slice of bread from the package 2, pass it over everybody’s hands and place it into the second plastic bag. Spray some water on it and seal it.
- Identify the plastic bags as 1 and 2.
Results – Part 1:
- Draw a circle and make your detailed drawing inside of it.
Results – Part 2:
Observe the plastic bags over a week and take notes/photos, every day, of how it is going.
Discussion: Answer the questions below in a text.
- Which bread slice presented changes first? Why?
- What are the differences between both bread slices after a week? Why?
- Where did the mold come from? Explain.
Conclusion:
Vocabulary:
fungi: spore-producing organisms that lack chlorophyll and often grow filaments (tiny root-like structures)
rust: fungal disease of plants that results in reddish or brownish patches
yeast: a microscopic fungus consisting of single oval cells that reproduce by budding, and are capable of converting sugar into alcohol and carbon dioxide