Tuesday, February 2, 2010

How can you tell the difference between the sexual structures of the fungus and the fungus itself?

For example, my text has a picture of some moldy bread, and claims the sexual structures of the fungi are called zygosporangia, and the fungus is called zygomycetes. Are the reproductive structures what you can see? And the actual fungus body is deep within the bread?How can you tell the difference between the sexual structures of the fungus and the fungus itself?
Their basic body plan constitutes a mass of netlike filaments called hyphae. The entire mass is called the mycelium. Most fungal hyphae are divided into cells by cross walls called septa. Some fungi are aseptate, lacking cross walls. They are said to be coenocytic. Some types of fungi contain lateral hyphae that absorb nutrients from other organisms, called haustoria.


Reproduction is accomplished by the release of sexual or asexual spores. For many species of fungi sexual reproduction is a contingency used when environmental conditions are difficult. Under favorable conditions asexual spores are produced by the millions and dispersed over a large area.


Haploid conditions prevail in the life cycles of most fungi. Conjugation occurs in many fungal species.





Fungi are classified into units called Divisions. There are 4 divisions based primarily on variations of sexual reproduction. The names of the divisions are based on the sexual structure that characterizes that group of fungi.


Example: Division Zygomycota: These are mostly terrestrial fungi that live in soil or on decaying plant or animal material. Their hyphae are coenocytic, with many haploid nuclei. Asexual spores, usually wind swept, are produced by structures called sporangia, at the tips of aerial hyphae. Sexual reproduction involves the formation of resistant bodies called zygosporangia that can remain dormant when the environment is too harsh for growth.How can you tell the difference between the sexual structures of the fungus and the fungus itself?
Fungus is made of mostly mycelia.


Mycelia are like.. roots of the fungus. They burrow underground and anchor the fungus.





Example mushroom, part of phylum basidiomycota.


Mushroom has these basidiospores 'hanging' under its gill.





The fungi in your example is probably Rhizopus. The sporangium are mainly on the surface of the bread (allows better dispersion of spores?).
The main part of the fungus that is there all the time is the hyphae (and a lot of hyphae make a mycelium)..which are fine thready loing things (like little root hairs). This is their feeding structure and goes through the food, ground, tree or wherever its feeding from.


The sex organs or sporangia of fungi are usually bigger and visible eg, mushrooms, toadstools or in smaller ones are little ball-like structures. This is where spores are produced (obviously the main exception are yeast which are single cells and reprduce by budding (assexual))
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