© 2008, ycmou. all rights reserved.1 online counseling resource ycmou elearning drive… school of...
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© 2008, YCMOU. All Rights Reserved. 1
Online Counseling ResourceYCMOU ELearning Drive…
School of Architecture, Science and TechnologyYashwantrao Chavan Maharashtra
Open University, Nashik – 422222, India
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OC-SBT081-CP01-05
Introduction
Programmes and Courses SEP – SBT081 – Unit 01
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Credits
Academic Inputs by Arun Punaji More.
M.Sc. (Microbiology) Experience: 11 Years [email protected]
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How to Use This Resource
Counselor at each study center should use this presentation to deliver
lecture of 40-60 minutes during Face-To-Face counseling.
Discussion about students difficulties or tutorial with assignments should
follow the lecture for about 40-60 minutes.
Handouts (with 6 slides on each A4 size page) of this presentation should
be provided to each student.
Each student should discuss on the discussion forum all the terms which
could not be understood. This will improve his writing skills and enhance
knowledge level about topics, which shall be immensely useful for end
exam.
Appear several times, for all the Self-Tests, available for this course.
Student can use handouts for last minutes preparation just before end
exam.
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Learning Objectives
After studying this module, you should be able to:
Describe characteristics of fungi.
Describe the characteristics of slime mould.
Describe the differentiating features of moulds and slime
mould.
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Introduction-1 We have observed many a times breads with
fine green or black lawn fibrous growth of organism or spoiling of pickles by whitish fibrous growth of organisms on the surface layer of pickle.
Many times you might have enjoyed the delicious mushroom pulao and mushroom pizza that your mother have prepared for you.
By the time you finished reading the above sentence you might have guessed that the fibrous growth spoiling the pickles and breads and the mushroom in your pizza are nothing but members of fungi.
Let us see more interesting characteristics and their feats of fungi in more details.
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Fungi-1 The members of fungi share many
common features with plant, animal cells and protozoa.
For example animal cells, plant cells and fungi are grouped as eukaryotic cells.
Like protozoa, fungi are chemoheterotrophic.
However the fungi differ from plant cells in that that the plant cells contain chlorophylls whereas the fungi do not contain chlorophylls.
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Fungi-2 Many fungi are used as foods. For
example mushroom and truffles. Many fungi are used to prepare foods such
as breads, some cheese and beverages such as soy sauce, citric acid and alcoholic drinks.
Many fungi are utilized as research tools. For example the Saccharomyces
cerevisiae is used in genetic engineering to produce recombinant strains of this yeast to manufacture many human proteins and some viral vaccine such Hepatitis B vaccine.
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Characteristics of Fungi-1 The kingdom fungi is classified under the
domain Eukarya. The members of fungi are eukaryotic cells. The fungi differ from animal cells in that
that they possess cell wall. The characteristic feature of fungi is that
their cell wall contain chitin, a nitrogenous complex polysaccharides.
Being heterotrophs, fungi play crucial role in the maintaining ecological balance by decomposing dead plant and animals recycling their nutrients.
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Characteristics of Fungi-2 They differ from plant cells in that that they do
not possess chlorophyll pigments. The unicellular members of fungi differ from
prokaryotes in that that they lack peptidoglycan in their cell walls; but their cell wall contain chitin, a nitrogenous polysaccharide.
Some members of fungi are unicellular; whereas some members of fungi are multicellular present in mycelial forms.
Some members of fungi, for example, can be present in more that one forms; such fungi are called as dimorphic fungi.
Yeast is example of dimorphic fungi.
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Characteristics of Fungi-3 Reproduction of Fungi:- Unicellular fungi reproduce by budding. Mycelial fungi reproduce asexual as well as
sexually by forming spores. Asexual spores depending upon their mode of
development are classified as follow: Sporangiospores:- developed inside the sac called
as sporagium. Chlamydospores:- developed inside the thick cell
of hypae. Conidiospore:- developed on the tip of hypae.
Types of conidiospores: Arthrospores – developed by fragmentation of hypae. Blastoconidia-- developed as buds on tips of hypae.
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Characteristics of Fungi-4 Reproduction of Fungi:- Sexual spores formation occur when
positive and negative hypae fuse together forming dikaryon, cell containing two positive and negative nuclei.
In the dikaryon the positive and negative nuclei recombine to form a single diploid nucleus after some time.
The diploid cells then undergo meiosis forming haploid nuclei which are surrounded by cytoplasm forming spores.
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Classification of Fungi-1 The fungi are divided into four divisions.
Zygomycota Ascomycota Basidiomycota Deuteromycetes
The first three divisions are on the basis types of sexual spores produced by the fungi; whereas the fourth division has no known sexual stage.
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Classification of Fungi-2 Zygomycota:-
Example of zygomycota is black bread molds such as Rhizopus and Nigricans.
The members of zygomycota reproduce by sexual as well as asexual mode.
In asexual mode of reproduction, asexual spores are produced called as sporangiospores.
In sexual mode of reproduction, sexual spores are produced called as zygospores.
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Classification of Fungi-3 Ascomycota:-
Examples of ascomycota are penicillium which produces antibiotic called as penicillin and saccharomyces which produces alcohols from sugars.
Truffle, the edible underground mushroom and pink bread molds, Neurospora are another examples of ascomycota.
The Neurospora is used as genetic tool in genetic engineering technology.
The members of ascomycota fungi produce sexual spores in sac called as asci.
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Classification of Fungi-4 Following figure show budding yeasts of
saccharomyces.
Fig: saccharomyces
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Classification of Fungi-5 Aspergillus, One of the member of
ascomycota produce conidiospores on the tip of hypae as shown below.
Fig: Conidiospores of Aspergillus
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Classification of Fungi-6 Basidiomycota:-
The edible and poisonous mushrooms are member of basidiomycota.
Cryptococcus neoformans, the important fungal species pathogenic to humans, is also one of the members of basidiomycota.
The basidiomycetes fungi reproduce by producing sexual spores called as basidiospores.
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Classification of Fungi-7 Deuteromycetes:-
The sexual stage of these fungi is unknown. However the rRNA analysis of these fungi
shows that they are genetically similar to the members of ascomycota.
Trichophyton, one of the members of deuteromycetes is medically important pathogenic fungi which causes ringworms to humans.
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Slime Molds-1 Slime molds are organism which look very
similar to the mycelial fungi but differ from the true fungi in two ways.
The slime molds do not possess cell wall like true fungi.
The slime molds up- take their foods by the process of phagocytosis or endocytosis.
The members of slime molds are excellent tools used in the study of molecular biology and developmental biology.
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Slime Molds-2 Two major groups of slime molds are:
Acellular slime molds Cellular slime molds
Acellular slime molds:- They are also called as plasmodial slime
molds. They can move like amoeba. They feed on bacteria and organic debris by
phagocytosing them. Plasmmodium is example of acellular slime
mold. Plasmodium produce haploid spores in
sporangium. The haploid spore germinate to produce
swimming myxamoebae in water.
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Slime Molds-3 Cellular molds:-
The cellular molds are all haploid organism. Cellular molds live as haploid individual cell
called as myxamoeba. Myxamoebae feed themselves by
phagocytosing yeast, bacteria and dead organic matter.
The myxamoebae reproduce by mitosis and cytokinesis.
Dictyostelium is example of cellular mold.
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Slime Molds-4 The picture of plasmodial slime mold is
shown below. This slime mold do not possess cell wall;
they can form the mass of protoplasm having numerous nuclei in it called as plasmodium.
Fig: Plasmodium of slime mold, Physarum
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Slime Molds-5 In the sexual life cycle of plasmodial
slime mold, diploid adult cells form sporangia in which haploid spores are produced; during the favorable condition the spore germinate into amoeboid or flagellated cells.
Fig: sporangia containing haploid spores of slime mold Stemonitis
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What We learn... Definition of Fungi General characteristics of fungi. Classification of fungi. General characteristics of slime molds.
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Critical Thinking Questions Why the slime molds are not called as true
fungi?
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Hints for Critical Thinking Questions
Definition of fungi not completely applicable to slime molds.
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Study Tips Book
Title:Title: Microbiology Author:Author: Robert W Bauman Publication:Publication: Benjamin Cummings, San Francisco
Book Title:Title: Microbiology, An Introduction Author:Author: Tortora and et al. Publication:Publication: Pearson education, Singapore
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End of the Presentation
Thank You!