Practical 3: Diversity of Fungi (eukaryotic cells)

What are fungi?

Fungi are eukaryotic organisms with chitin cell walls that range from unicellular yeasts to multicellular molds and mushrooms.

What is hyphae?

Hyphae are long, branching filaments that make up the body of fungi.

What is mycelium?

A mass of hyphae that forms the vegetative part of a fungus.

What is the difference between septate and coenocytic hyphae?

Septate hyphae have cross-walls (septa) dividing the cells, while coenocytic hyphae lack septa, forming a continuous multinucleated cytoplasm.

What is the role of reproductive hyphae?

They produce spores for reproduction.

What are spores?

Reproductive cells of fungi that can develop into new organisms without fertilization.

What is budding?

A form of asexual reproduction in yeast where a small cell grows from a larger parent cell.

What are conidia?

Asexual spores produced by filamentous fungi like Penicillium.

What is a lichen?

A symbiotic association between a fungus and a photosynthetic organism (green algae or cyanobacteria).

What are the major groups of fungi studied in this lab?

Yeasts (unicellular fungi), Molds (filamentous fungi like Rhizopus and Penicillium), Mushrooms (large fruiting bodies of fungi), and Lichens (symbiotic fungi).

How do yeast cells appear under a microscope?

Round or oval, larger than bacteria, often showing budding.

What is the function of intracellular granules in yeast?

They store nutrients.

What staining technique is used for yeast?

Yeast is stained with iodine to observe intracellular granules.

What is Rhizopus?

A common mold that grows on bread and produces sporangiospores inside sporangia.

What is the function of rhizoids in Rhizopus?

They anchor the fungus and absorb nutrients.

What structure contains Rhizopus spores?

The sporangium.

Are Rhizopus hyphae septate or coenocytic?

Coenocytic (non-septate).

How does Penicillium reproduce?

By producing conidia, asexual spores.

What is the shape of Penicillium conidia?

Chains of round spores at the tips of specialized hyphae.

What color does Penicillium appear in culture?

Blue-green.

What are the main parts of a mushroom?

Cap (top part), Stipe (stalk), and Gills (underside of cap, where spores are produced).

What are basidiospores?

Sexual spores of mushrooms produced on basidia.

Where are the vegetative hyphae of a mushroom found?

Underground, forming a network called mycelium.

Which part of the mushroom do we eat?

The fruiting body, which includes the cap and stalk.

What are lichens composed of?

A fungal component (provides structure and protection) and a photosynthetic component (provides food via photosynthesis).

Why are lichens important in environmental studies?

They are bioindicators of air pollution.

How is yeast prepared for microscopic observation?

A drop of yeast suspension is mixed with iodine, a cover slip is placed over it, and it is observed under high power and oil immersion.

How do you prepare a slide of Rhizopus?

A drop of Lactophenol is placed on a slide, a small piece of Rhizopus mycelium is added, a cover slip is placed on top, and it is observed under a microscope.

How do you observe Penicillium in blue cheese?

A small piece of blue cheese is placed on a slide, a drop of water is added, and the sample is observed under a microscope.

How is a mushroom examined?

A longitudinal section (cut in half) is made, a small piece of gill tissue is placed on a slide with water, and it is observed under a microscope to see basidiospores.

How is a lichen observed?

A prepared slide of lichen is examined under a microscope, and the fungal and algal components are identified and drawn.

What is the role of fungi in the ecosystem?

They decompose organic matter and recycle nutrients.

How do fungi differ from plants?

Fungi have chitin cell walls (plants have cellulose), fungi are heterotrophic (plants are autotrophic), and fungi absorb nutrients from their surroundings.

How do fungi reproduce?

Asexually (by budding, fragmentation, or spores) and sexually (by spore formation in specialized structures).