7.4.3 Basidiomycota (club fungi)
Basidiomycetes are also known as club fungi because they produce club-shaped reproductive structures known as basidia. It is a hyphal cell at the tip of which the sail develops sexual spores (basidiospores).
Basidiomycota fora run not only includes mushrooms, puffballs, and shelf fungi but also important pathogens like rusts and smuts. The mycelium (fruiting body) in club fungi exists
Do you mean in three forms that are primary, secondary, and tertiary Rests and m mycelium? Primary mycelium is monokaryotic while secondary mycelium is formed by an interaction with primary mycelium which now becomes a dikaryotic cell. When the mycelium becomes more complex and gives rise to fruiting bodies (Basidiocarp), it is called tertiary masses similar to 3001 In mycelium. Spots are caused by Puccinia
Mushroom (Agaricus) consists of a mass of white-branched, thread-like separate hyphae that occur mostly we so below the ground.
Reproduction in club fungi (Basidiomycota):
Club fungi usually reproduce sexually, occasionally asexually by conidiophores. The mushroom itself is called the fruiting body and consists of a stalk and a cap. It is known as a basidiocarp. The lower surface of the cap usually consists of many thin perpendicular plates called gills. They radiate from the stalk to the edges of the cap. In the gills, the haploid
nuclei of dikaryotic cells fuse to form a diploid zygote.
A zygote is the only diploid structure in its life cycle. Each zygote immediately undergoes meiosis to produce four (+) and (-) haploid basidiospores in the gills.
The gills burst and spores are released from the fruiting body and carried by wind or animals to a suitable moist land. Each "+ve and-ve" mycelia grows towards each other and cytoplasms fuse (plasmogamy) but nuclei do not fuse.
Thus each cell of secondary mycelium contains two haploid nuclei, grows, and forms a compact mass called buttons, along the mycelia. Each button grows into a fruiting body (tertiary mycelium). The dikaryotic stage ends and a new diploid stage begins when (n+ n) cells fuse to form a zygote in the basidium.
7.5 Importance of Fungi
Fungi are both useful and harmful to human beings and other organisms. Many fungi are palatable, used as food, and some help in making various chemicals. It also causes diseases in human beings and other living things. They spoil and decay our food and many other articles.
7.5.1 Importance of yeast
Saccharomyces cerevisiae (yeast) has many benefits to mankind, such as 1794 bread making.
For manufacturing bread yeast is mixed with white flour. The CO, produced by yeast becomes trapped in the dough as bubbles, causing the dough to rise, this is what gives leaven bread its light texture. The CO, and alcohol produced by yeast are evaporated during baking. The flavor and quality of bread are attained by selecting different strains of yeast.
Brewing (Production of Alcohol) Ethyl alcohol (wine, beer) is prepared by the fermentation of cereals, potatoes, fruit, sugars, etc.
CHO+yeastmes 2C,H,OH+2C0, Ethanol
In genetic research: yeasts have been used in biological research; especially study of mutation, and genetic recombination and to test the effects of many chemicals and medicines. Yeasts possess plasmids in their genome, thus like bacteria can be used as gene vectors. Yeast is the only organism which is used for the formation of hepatitis B vaccine.
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