Skip to main content

Fungi BSc 1st semester Allahabad University

 FUNGI


  • The word fungus has been taken from Latin which means mushroom.
  • The fungi are  Achlorophyllous and heterotrophic thallophytes.
  • Their plant body consists mostly of a thallus, made up of hyphae which constitute mycelium.
  • The study of fungi is known as mycology and the scientist who is concerned with fungi is called mycologist.


General Introduction :-

  • fungi is eukaryotic and multicellular organism fungi have absorptive type nutrition.
  • Study of fungi is called - Mycology
  • The father of mycology - De Barry
  • Father of Indian mycology - E. J. Butler
  • Origin of fungi - Mykas - (Mushroom)

General characteristics of fungi : -

  • Fungi are eukaryotic organisms means they have true nucleus which are enclosed in membranes.
  • They are non - vernacular organisms they do not have vascular system. Xylem and phloem are absent.
  • Fungi have cell walls its made of chitin the unit of chitin is N-Acetyl glucosamine.
  • There is no embryonic stage for fungi.
  • The vegetative body of fungi may be unicellular or composed of colour less and microscopic threads like filament structure is called hyphae.
  • Hyphae can grow and form a network or group is  called Mycelium.


Mycelium are two types:-

  • Septate
  • Aseptate (non-septate)


Aseptate hyphae are also called coenocytic hyphae.


NUTRITION IN FUNGI

  • Fungi are heterotrophic organisms. They obtain its food and energy from organic substance plant and animal matters.
  • Fungi have an absorptive mode of nutrition; it means they absorb the food from the surrounding.
  • Fungi grow best in an acidic environment.
  • Nutrition in fungi - They are saprophytes -(gets energy from dead matters) or parasites (living in a host) or the symbiotic (Mutually beneficial).
  • Those saprophytes and parasites may be obligate or facultative.
  • Obligate parasites always take the food from living host.
  • Obligate saprophytes always take the food from dead organic matter.
  • Ex. of obligate parasite- puccinia, Albugo.
  • Ex. of obligate saprophytes- Mucus.
  • Facultative parasites are generally seprophytes but under certain  condition they become parasite. Ex. of facultative parasites- Aspergillus and penicillin.
  • Facultative seprophytes generally parasite but under certain condition they become seprophytes . Ex. Alternaria.
  • Some fungi may be grow in the form of symbiotic association. Ex. Lichen (Algae and fungi) Mycorrhiza etc.


REPRODUCTION IN FUNGI

  1. Vegetative method 
  2. Asexual method
  3. Sexual method



  • Fungi are mainly reproduced through vegetative and asexual method condition but during unfavorable condition fungi may be reproduces through sexual reproduction method.
  • Fragmentation is the most common vegetative reproduction in fungi.
  • During the asexual reproduction fungal members produces some specific structure or a sexual spore which have the ability to develop new thallus.
  • Budding and fission is also a part of asexual reproduction (mainly observed in yeast).

In fungal member present two types of spores 

  1. Zoospores (motile spores)
  2. Aplanospores (Non motile spores)

→The sexual spore are either zoospores(motile spores) or Aplanospores(non motile spores) or chlamydospores- thick walled non motile spores.

→Conidia are also formed during Asexual reproduction but they are exogenous in origin that is not provided inside sporangium.


ECONOMIC IMPORTANT OF FUNGI

→Fungi are important for many reasons , including

  • As Food - fungi are used to produce fermented foods like beer, wine and bread. Some mushrooms also edible like agaricus, morchella etc Yeast is an important source of vitamin B and D.
  • As medicine- several fungi are used in the production of medicines; fungi are a source of many drugs, including penicillin, statins and taxol. 
  • Fungi in industry - Alcoholic fermentation with the help of fungi is the basis of brewing industries. Wine is produced by fermenting rice with Aspergillus oryzae.  Saccromyceases cerevisiae is used in the production of beer. And also used in bakery products, cheese industry.
  • Fungi in Agriculture - fungi play an important role in agriculture in various ways Some fungi increases the rate of soil fertility by secreting some enzymes which break down the organic complexes.
  • Environmental protection - fungi help break down pollutants like plastic, pharmaceuticals and oil.

oil.

CLASSIFICATION IN FUNGI 

→A more natural system of classification of fungi was proposed by Ainsworth. 

  • Division 
    • Myxomycota (not true fungi)
    • Eumycota (true fungi)

Eumycota divided into 5 sub division

  1. Mastigomycotina
  2. Zygomycotina
  3. Ascomycotina
  4. Basidomycotina
  5. Deuteromycotina


Mastigomycotina - 

  • Oomycetes
  • Aseptate hyphae, mycelium well developed 
  • Unicellular, sexual spore are present - Oospore  
  • Asexual spore- Zoospore 

Types of flagella 

  1. Anterior side (Tinsel)
  2. Posterior side (Whiplash)  


Sexual reproduction through gametangeal contact .
genus of Oomycetes family- Phytophthora and Albugo .









Short Notes-

Heteroecism – heteroecism in fungi refers to a parasitic fungus like certain rust that requires two or more different hosts to complete there life cycle. 

For example – Puccinia graminis

Clamp connection- Clamp connection are specialized structures in certain fungi, specifically basidiomycetes. These are hook like structures that form between two hyphal cells in some fungi. They help maintain the dikaryotic condition in each new cell by ensuring that each daughter cell receives a nucleus from each parent cell.

Obligate parasite – Those fungi which obtain their nutrition from other living host are known as parasites. Obligate parasites are those fungi which survive only on living host. For example – Puccinia, Albugo

Heterothallism – heterothallism can be defined as condition where two complementary mating types are needed for sexual reproduction.

It first discovered in Mucor. He regarded (+) and (-) strains of heterothallic species to two different sexes (male and female).

It is two types- 

  • Morphological – the male and female sex organs which are present in two closely associated mycelia are morphologically different.
  • Physiological – In this the sexual reproduction takes place by two morphologically similar but physiologically different hyphae. 







Labels:
Location: 556/23/413, Kidwai Nagar, Allahpur, Prayagraj, Uttar Pradesh 211006, India

Comments

Post a Comment

Popular posts from this blog

Mechanism of Organic Reactions BSc 1st semester notes

MECHANISM OF ORGANIC REACTIONS  Conversion of a chemical compound into another chemical compound is known as a chemical reaction. Organic reactions usually involve the fission and formation of covalent bonds. Organic reactions take place in accordance with general fundamental concepts of thermodynamics. Usually, the sequence and timing of these bonds breaking and bond forming processes are important in the study of these reactions. These processes may occur separately, for example, bond breaking may proceed bond formation or vice-versa resulting in a step-wise reaction. ARROW NOTATION (FORMALISM) Organic reactions usually involve the fission and formation of covalent bonds. The covalent bond is often represented as a dash (-) and the movement of a pair of electrons is shown by a curved arrow in fact, arrow formalism (notation) is very important for organic reactions. Arrows in chemical drawing have specific meanings. Just as it is important to learn the structural representa...
Post a Comment
Read more Topics »

Bacteria BSc 1st semester

BACTERIA  Bacteria - Bacteria are microscopic and single - celled living organisms. Bacteria is discovered by Antony van Leeuwenhoek from rain water. they are omni present . It placed under Protista kingdom. General Characteristics of Bacteria - Bacteria are prokaryotic (primitive nucleus), nucleus not surrounded by nuclear membrane e.g., incipient nucleus or nucleoid. Due to the presence of a Rigid cell wall bacteria maintain a definite shape through they varies as shape, size and structure. In general bacteria are between 0.2 and 2.0 micrometer - the average size of most bacteria. One group of bacteria called the mycoplasma, the measure about 0.25 micron and are the smallest cell known so far, they were formally known as PPLO (Pleuropneumonia like organisms). They are omnipresent, found in all possible habitats one can think of. Most of the bacteria have heterotrophic mode of nutrition, i.e., they obtain their readymade food directly from external agency, and may be ...
Post a Comment
Read more Topics »

Virus BSc 1st semester Allahabad University

  Viruses   (Nature, Structure, transmission and multiplication of viruses ) The name virus (Latin virus = venom of poisonous fluid), it was discovered by D Ivanowasky. General Characteristics of Viruses-  Viruses are sub-microscopic particles which have been studied in detail by electron microscope using selective techniques. A simple virus particle often designated as virion, consists of a nucleic acid core of genetic material (genome) enclosed within a protein coat. The amount of protein in different viruses varies from 60-95 per cent and the rest is nucleic acid. Viruses are very small in size, varying over a wide range from 20-350 nm.  The largest are the orthopoxviruses, measuring about 240 nmx300 nm, i.e., approximately 1/10 the size of a red blood cell. The complex bacteriophages are about 65 nm x 200 nm.  Among the smallest viruses known are the enteroviruses, which are less than 30 nm in diameter. Viruses differ fundamentally from cellular organisms in...
1 comment
Read more Topics »