A fungus (plural: fungi) is a kind of living organism: yeasts, moulds and mushrooms are types of fungi. The fungi are a separate kingdom of living things, different from animals and plants.
Fungi have cells with nuclei. Their cell walls contain chitin, unlike the cell walls of plants, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, called the Eumycota or Eumycetes. They share a common ancestor and are monophyletic group.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Similar to animals, fungi are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesise. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems.Fungi have cells with nuclei. Their cell walls contain chitin, unlike the cell walls of plants, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, called the Eumycota or Eumycetes. They share a common ancestor and are monophyletic group.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Similar to animals, fungi are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesise. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems.
Fungi.docx
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A fungus (plural: fungi) is a kind of living organism: yeasts, moulds and mushrooms are types
of fungi. The fungi are a separate kingdom of living things, different from animals and plants.
Fungi have cells with nuclei. Their cell walls contain chitin, unlike the cell walls of plants, which
contain cellulose. These and other differences show that the fungi form a single group of
related organisms, called the Eumycota or Eumycetes. They share a common ancestor and
are monophyletic group.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists
is chitin in their cell walls. Similar to animals, fungi are heterotrophs; they acquire their food by
absorbing dissolved molecules, typically by secreting digestive enzymes into their environment.
Fungi do not photosynthesise. Growth is their means of mobility, except for spores (a few of
which are flagellated), which may travel through the air or water. Fungi are the principal
decomposers in ecological systems.
Their basic mode of life is saprophytic: a fungus breaks down dead organic matter around it, and
uses it as food.[1]p107
Structure[change | change source]
Reproduction[change | change source]
Fungi reproduce both sexually and asexually. Some fungi grow mushrooms: these are fruiting
bodies. Under the cap there are gills; the gills bear sporesthat will disperse, and may develop into
new fungi. Otherwise, fungi use a sporangium to bear asexual spores by mitosis, or sexual spores
by meiosis. The spores are haploid.
Fungi may be single celled or multicellular. Yeast is singlecelled, and reproduces either sexually
or asexually..
Mycelium
The mycelium is the vegetative (nonreproductive) part of a fungus. It is usually underground (or
inside some other substance), and made of filaments called hyphae.
Hyphae[change | change source]
Hyphae look like threads, or rootlets. The mat of hyphae may be very thickly woven. The fungus
uses them to extract nutrients.
Hyphae are usually syncytia. This means the cell walls (septa) are mostly not complete, and
the cell nuclei are not separated from each other as in normal cells. Details differ between
species.
Symbiosis[change | change source]
Symbiosis means living together. Lichens are a symbiosis between a fungus and
an alga or bacterium. In this partnership the algal cells live inside the fungus tissue. The end
result is a new matlike lifeform which clings to rock and other surfaces. About 20% of all fungi
are lichenized.
Another important kind of symbiosis is mycorrhiza. This is when a fungus lives inside plant
roots; most trees have mycorrhizal roots, and so do many crop plants. Both sides benefit in this
arrangement.
Pathogens] Some fungi cause crop diseases; others cause serious disease in humans. Some are highly
poisonous: never eat a mushroom picked in the wild unless you know what you are doing.
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Uses[change | change source]
Edible fungi are widely used as human food. Certain types of cheese need a fungal
species to be added. The fungi give a unique flavor and texture to the cheese.
Some fungi produce psychotropic (mindaltering) substances. Several species, most
notably Psilocybin mushrooms (colloquially known as magic mushrooms), are taken for
their psychedelic properties, so they are illegal in many countries around the world.
In modern times, some fungi (for example, Penicillin) have been used as a source
of antibiotics. The antibiotics are produced by many fungi as a natural defence
against bacteria.
Characteristics
Fungal hyphae cells
Hyphal wall
1.
Septum
2.
Mitochondrion
3.
4.
Vacuole
Ergosterol crystal
5.
Ribosome
6.
7.
Nucleus
Endoplasmic reticulum
8.
Lipid body
9.
Plasma membrane
10.
11.
Spitzenkörper
Golgi apparatus
12.
Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered
fungi to be members of the plant kingdombecause of similarities in lifestyle: both fungi and
plants are mainly immobile, and have similarities in general morphology and growth habitat.
Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit
bodies, which sometimes resemble plants such as mosses. The fungi are now considered a
separate kingdom, distinct from both plants and animals, from which they appear to
have divergedaround one billion years ago.[11][12] Some morphological, biochemical, and genetic
features are shared with other organisms, while others are unique to the fungi, clearly separating
them from the other kingdoms:
Shared features:
With other eukaryotes: Fungal cells contain membrane
bound nuclei with chromosomes that contain DNA with noncoding
regions called introns and coding regions called exons. Fungi have membranebound
cytoplasmic organelles such as mitochondria, sterolcontaining membranes,
and ribosomes of the 80S type.[13] They have a characteristic range of soluble carbohydrates
and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides,
(e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals[14]).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require
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preformed organic compounds as energy sources.[15]
With plants: Fungi have a cell wall[16] and vacuoles.[17] They reproduce by both sexual and
asexual means, and like basal plant groups (such as ferns and mosses) produce spores.
Similar to mosses and algae, fungi typically have haploid nuclei.[18]
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce
the amino acid Llysine in specific biosynthesis steps, called the α aminoadipate pathway.[19]
[20]
The cells of most fungi grow as tubular, elongated, and threadlike (filamentous)
structures called hyphae, which may contain multiple nuclei and extend by growing at their
tips. Each tip contains a set of aggregated vesicles—cellular structures consisting
of proteins, lipids, and other organic molecules—called the Spitzenkörper.[21] Both fungi
and oomycetes grow as filamentous hyphal cells.[22] In contrast, similarlooking organisms,
such as filamentous green algae, grow by repeated cell division within a chain of cells.
[14] There are also singlecelled fungi (yeasts) that do not form hyphae, and some fungi have
both hyphal and yeast forms.[23]
In common with some plant and animal species, more than 70 fungal
species display bioluminescence.[24]
Unique features:
Some species grow as unicellular yeasts that reproduce by budding or binary
fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to
environmental conditions.[23]
The fungal cell wall is composed of glucans and chitin; while glucans are also found in
plants and chitin in the exoskeleton of arthropods,[25][26] fungi are the only organisms that
combine these two structural molecules in their cell wall. Unlike those of plants and
oomycetes, fungal cell walls do not contain cellulose.
Mycology is the branch of biology concerned with the systematic study of fungi,
including their genetic and biochemical properties, their taxonomy, and their use to
humans as a source of medicine, food, and psychotropic substances consumed for
religious purposes, as well as their dangers, such as poisoning or infection. The field
of phytopathology, the study of plant diseases, is closely related because many plant
pathogens are fungi.[42]
In 1729, Pier A. Micheli first published descriptions of fungi.
The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a wellpreserved
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mummy of a 5,300yearold Neolithicman found frozen in the Austrian Alps, carried two
species of polypore mushrooms that may have been used as tinder(Fomes fomentarius),
or for medicinal purposes (Piptoporus betulinus).[43] Ancient peoples have used fungi as
food sources–often unknowingly–for millennia, in the preparation of leavened bread and
fermented juices. Some of the oldest written records contain references to the destruction
of crops that were probably caused by pathogenic fungi.[44]
History
Mycology is a relatively new science that became systematic after the development of
the microscope in the 17th century. Although fungal spores were first observed
by Giambattista della Porta in 1588, the seminal work in the development of mycology is
considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum
genera.[45] Micheli not only observed spores but also showed that, under the proper
conditions, they could be induced into growing into the same species of fungi from which
they originated.[46] Extending the use of the binomial system of nomenclature introduced
by Carl Linnaeus in his Species plantarum (1753), the Dutch Christian Hendrik
Persoon (1761–1836) established the first classification of mushrooms with such skill so
as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–
1878) further elaborated the classification of fungi, using spore color and various
microscopic characteristics, methods still used by taxonomists today. Other notable early
contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph
Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis
René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea
Saccardo. The 20th century has seen a modernization of mycology that has come from
advances in biochemistry, genetics, molecular biology, and biotechnology. The use
of DNA sequencing technologies and phylogenetic analysis has provided new insights
into fungal relationships and biodiversity, and has challenged traditional morphology
based groupings in fungal taxonom
ː
yeast [ji st] дрожжи
moulds [m ldz] плесневые грибки
əʊ
mushrooms [ m r mz] лесные грибы
ˈ ʌʃ ʊ
s] целлюлозаж, клетчатка
ɪˈʤ ɪ
est v enza m] пищеварительный фермент
ʊ ə
l r] многоклеточный
ɪ
ˈ
multicellular [m lt selj
ʊ ə
l ] одноклеточный
ˈ
mycelium [ma si l m] мицелий
chitin [ k t ŋ] хитин
ʊ əʊ
l
cellulose [ selj
ˈ ɪ ɪ
ˈ
digestive enzyme [d
ʌ ɪˈ
ː ɪˈ
ɪˈ
ɪ ː
unicellular [ ju n selj
ː ɪə
hyphae [ ha fi ] гифы
ˈ
nutrients [ nju tr nts] питательность
ː ɪə
ˈ
symbiosis [s mb
ɪ
ɪˈəʊ ɪ
s s] симбиоз ˈ ɒ ə ɑː
chloroplast [ kl r pl
ə əˈ
heterotrophic [het r
træf k] гетеротрофный
ɪ
st] хлоропласт
5
fission [f n] деление
ɪʃ
mycology [ma k l
ɪˈ ɔ əʤɪ
] микология
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