Characteristics of fungi
Fungi are organisms that lack chlorophyll and therefore do not make food by photosynthesis. Many fungi consist of thread-like hyphae forming a network called a mycelium. Their cell walls commonly contain chitin.
Nutrition in fungi
Fungi obtain food by secreting digestive enzymes onto organic material and absorbing the soluble products. A fungus may be a decomposer, a parasite, or a mutualistic partner. Decomposers recycle nutrients by breaking down dead organisms.
Reproduction
Many fungi reproduce asexually by producing spores. Spores are small, light, and produced in large numbers, allowing them to be dispersed by air. Some fungi also reproduce sexually when compatible hyphae fuse and genetic material is combined.
Mushroom cultivation
- Prepare a clean, moist growth medium containing suitable organic material.
- Introduce mushroom spawn into the medium.
- Keep the growing material warm, moist, and protected from contamination.
- Provide ventilation and harvest mushrooms when they are mature.
Importance of fungi
- They decompose dead material and recycle mineral nutrients.
- Yeast is used in baking and fermentation.
- Some fungi are eaten as food.
- Some produce medicines.
- Others cause crop diseases, food spoilage, and human infections.
Revision questions
- Why can fungi not photosynthesise?
- Define hypha and mycelium.
- Explain how a decomposer fungus obtains food.
- State two useful and two harmful effects of fungi.
