since the dawn of civilization their have been many attempts to classify living organism.it was done instinctively not using criteria that were scientific but borne out of a need to use organism for our use for food, shelter and clothing.Aristotle was the earliest to attempt more scientific basis for classification.He used simple morphological characters to classify plants in to trees,shrubs and herbs.He also divided animals in to two groups, those which had red blood and those that it did not.
In Linnaeus time a TWO KINGDOM System of classification with PLANTAE and ANIMALIA kingdom was developed that included all plants and animals respectively.This wsas used till very recently.This system did not distinguish between the eukaryotes and prokaryotes, unicellular and multicellular organism and photosynthetic and non photosynthetic organism.Classification of organism into plants and animals was easily done to understand, inspite, a large number of the organism did not fall to either category.Hence the two kingdom used for a longtime was found inadequate.A need also felt including, besides gross morphology, other characteristics like cell structure,nature of wall mode of nutrition habitat, methods of reproduction, evolutionary relation ships, etc...Classification system for the living organism have hence, undergone several changes over time .
R.H.Whittaker (1969) proposed a FIVE KING DOM CLASSIFICATION The kingdom defined by him were named MONERA,PROTISTA, FUNGI,PLANTEA $ ANIMALIA.The ain criteria for the classification used by him include cell structure,thallus organism, mode of nutrition, reproduction and phylogenetic relationship.
Let us look at this five kingdom classification to understand the issues and consideration that influenced the classification system.Earlier classification system included bacteria , blue green algae,fungi,mosses,ferns,gymnosperms and the angiosperms under plants.It also grouped together the unicellular organism and multicellular ones, say for example,chlamydomonas and spirogyra were placed together under algae.the fungi were placed in a separate kingdom -kingdom fungi.All prokaryotic organism were grouped together under kingdom monera and unicellular organism were placed in kingdom protista.
In this chapter we will study characteristics of kingdom monera,protista,fungi system classification.commonly referred to the plants and animals, kingdom,respectively.
Bacteria are the sole member of the kingdom monera.They are the most abundant micro organism.Bacteria occur almost everywhere.Hundreds of bacteria are present in handful soil.They also live in extreme habitats such as hot spring, deserts, snow and deep oceans where very few other life for can survive.
Bacteria are grouped for under four categories based on their shapes.
Though the bacterial structure is very simple they are very complex in behaviour.compared to many other organism , bacteria as a group show the most extensive metabolic diversity.They may be photosynthetic autotrophic or chemosynthetic autotropic.
Commonly know as sac fungi the ascomycetes are unicellular, eg., yeast or multicellular, eg , penicillium . They are saprophytic, decomposers parasitic or coprophilous . Myceliumis branched producing and septate. The asexual spores are conidia produced exogenously on the special mycelium called conidiophores . Conidia on germination produce mycelium. Sexual spores are called ascopores which are produced endogenously in sac like asci. These asci are arranged in different types of fruiting bodies called ascocarps. Some eg are Aspergillus, Claviceps and Neurospora. Neurospora is used extensively in biochemical and genetic work. Many members like morels and buffles are edible and are considered delicacies.
In this chapter we will study characteristics of kingdom monera,protista,fungi system classification.commonly referred to the plants and animals, kingdom,respectively.
since the dawn of civilization their have been many attempts to classify living organism.it was done instinctively not using criteria that were scientific but borne out of a need to use organism for our use for food, shelter and clothing.Aristotle was the earliest to attempt more scientific basis for classification.He used simple morphological characters to classify plants in to trees,shrubs and herbs.He also divided animals in to two groups, those which had red blood and those that it did not.
In Linnaeus time a TWO KINGDOM System of classification with PLANTAE and ANIMALIA kingdom was developed that included all plants and animals respectively.This wsas used till very recently.This system did not distinguish between the eukaryotes and prokaryotes, unicellular and multicellular organism and photosynthetic and non photosynthetic organism.Classification of organism into plants and animals was easily done to understand, inspite, a large number of the organism did not fall to either category.Hence the two kingdom used for a longtime was found inadequate.A need also felt including, besides gross morphology, other characteristics like cell structure,nature of wall mode of nutrition habitat, methods of reproduction, evolutionary relation ships, etc...Classification system for the living organism have hence, undergone several changes over time .
In Linnaeus time a TWO KINGDOM System of classification with PLANTAE and ANIMALIA kingdom was developed that included all plants and animals respectively.This wsas used till very recently.This system did not distinguish between the eukaryotes and prokaryotes, unicellular and multicellular organism and photosynthetic and non photosynthetic organism.Classification of organism into plants and animals was easily done to understand, inspite, a large number of the organism did not fall to either category.Hence the two kingdom used for a longtime was found inadequate.A need also felt including, besides gross morphology, other characteristics like cell structure,nature of wall mode of nutrition habitat, methods of reproduction, evolutionary relation ships, etc...Classification system for the living organism have hence, undergone several changes over time .
R.H.Whittaker (1969) proposed a FIVE KING DOM CLASSIFICATION The kingdom defined by him were named MONERA,PROTISTA, FUNGI,PLANTEA $ ANIMALIA.The ain criteria for the classification used by him include cell structure,thallus organism, mode of nutrition, reproduction and phylogenetic relationship.
Let us look at this five kingdom classification to understand the issues and consideration that influenced the classification system.Earlier classification system included bacteria , blue green algae,fungi,mosses,ferns,gymnosperms and the angiosperms under plants.It also grouped together the unicellular organism and multicellular ones, say for example,chlamydomonas and spirogyra were placed together under algae.the fungi were placed in a separate kingdom -kingdom fungi.All prokaryotic organism were grouped together under kingdom monera and unicellular organism were placed in kingdom protista.
In this chapter we will study characteristics of kingdom monera,protista,fungi system classification.commonly referred to the plants and animals, kingdom,respectively.
1. KINGDOM MONERA
Bacteria are the sole member of the kingdom monera.They are the most abundant micro organism.Bacteria occur almost everywhere.Hundreds of bacteria are present in handful soil.They also live in extreme habitats such as hot spring, deserts, snow and deep oceans where very few other life for can survive.
Bacteria are grouped for under four categories based on their shapes.
Though the bacterial structure is very simple they are very complex in behaviour.compared to many other organism , bacteria as a group show the most extensive metabolic diversity.They may be photosynthetic autotrophic or chemosynthetic autotropic.
2. ARCHAEBACTERIA
These bacteria are the special since living the most harsh habitats such as extreme salty areas ,hot spring and marshy areas. Achaebacteria differ from the other bacteria in having different cell wall structure and this features this responsible for their survival extreme condition..They are the responsible for the production of the methane from dung of these animals.
3.EUBACTERIA.
There are thousands of different eubacteria or true bacteria.they are characterised by the presence of rigid cell wall and if motile a flagellum.The cynobacteria have chlorophyll a similar to green plants are the photosynthetic autographs .
Bacteria reproduce mainly by fission .Sometimes, under unfavourable condition they produce spores.They also reproduce by a sort sexual production by adopting a primitive type of DNA transfer from one bacterium to other.
heterotrophic bacteria are the most abundant in nature.The majority are the important decomposers. many of them have a significant impact on human affairs.They helpful in making curd on milk, production of antibiotics fixing nitrogen in legume roots etc..Some are the pathogen causing damage to human being, crops farm animals and pets.Cholera, typhoid, tetanus, citrus, canker are well known diseases caused by different bacteria.
The mycoplasmas are the organism that living cell known as completely lack of cell wall.Many mycoplasma are the pathogenic in animals and plants.
4. KINGDOM PROTISTA
All single-celled eukaryotes are placed under Protista, but the boundaries of this kingdom are not well defined.What may be 'a photosynthetic protistan' to one biologist may be 'a plant' to another. In this content we include Chysophytes,Dianoflagellates, Euglenoids, Slime moulds and Protozoans nder Protista. Members of Protista are primarily aquatic. This kingdom forms a link with plant, animals and fungi. Being eukaryotes, the protistan cell body contain a well defined nucleus and other memberance-bound ornganelles. some have flagella or cilia. Protista reproduce asexually and sexually by a process involving cell fusion and zygote formation.
5. CHRYSOPHYTES
This group include diatoms and golden algae(desmid). They are found in fresh water as well as in marine environments. They are microscopic and float passively in water currents (plankton). Most of them are photosynthetic. In diatoms the cell walls form two thin overlapping shells, which fit together as in a soap box. The walls are embedded with silica and thus the walls are indestructible. Thus, diatoms have left behind large amount of cell wall deposits in their habitat; this accumulations over billons of years ins reffered to as 'diatomaceous earth'. Being gritty this soil is used in polishing, filtration of oils and syrups. Diatoms are the cheif 'producers' in the oceans.
6. DIANOFLAGELLATES
These organism are the mostly marine and photosynthetic.They appear yellow, green, brown, blue or red depending on the main pigments presents in their cells.The cell wall has stiff cellulose plates on the outer surface. Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the plates.
7. EUGLENOIDS
Majority of the are fresh water organism found in stagnant water. Instead of a cell wall, they have a protein rich layer called pellicle which makes their body flexible. They have two flagella, a short and a long one. Though they are photosynthetic in the presence of sunlight, when deprvied of sunlight, they behave like heterotrops by predating on other smaller organisms. Interrestingly, the pigments of euglenoids are identical to those present in higher plants. Example:euglena
8. SLIME MOULDS
Slime moulds are saprophytic protists.The body moves along decaying twigs leaving engulfing organic materials. Under suitable condition, they fro an aggregation called plasmodium which may gross and spread over several feet. During unfavourable condition the plasmodium differentiates and forms fruiting bodies bearing spores up their tips.The spores posses true wall. They are extremely resistant and survive for many year even under adverse condition.The spores are dispersed by air current.
9. PROTOZOANS
All the protozoans are the heterotrophs and live as the predators or parasites. they are believed to be primitive relatives of animals. They are four major groups of protozoans.
Amoeboid protozoans ; These organism live in fresh water, sea water or moist soil.They moved and capture their pray by putting out as in amoeba.Marine forms have a silica shells on their surface.Some of them such as Entamoeba are parasites.
Flagellated protozoans; The members of this group are the either free living or parasitic. They have flagella.The parasitic forms cause diaseases such as sleeping sickness.
ciliated protozoans; these are aquatic actively moving organism because of these presence of thousands of cilia.They have a cavity gulletthat opens to the outlet of the cell surface.the coordinated movement of the rows of cilia causes the water laden with food to be steered in to the gullets.
Sporozoans; this include diverse organism that have an infectious spore-like stage in their life cycle. The most notorious is PLASMODIUM which causes malaria which has staggering effect on human population.
Sporozoans; this include diverse organism that have an infectious spore-like stage in their life cycle. The most notorious is PLASMODIUM which causes malaria which has staggering effect on human population.
KINGDOM FUNGI
The fungi constitute a unique kingdom of heterotrophic organism.They show a great diversity in morphology organism.When your breads developed a mould or your orange rots it is because of fungi.white spots seen on mustard leaves are due to parasitic fungus. some unicellular fungi the cause diseases
most fungi are the heterotrophic and absorb soluble organic matter from dead substrates and hence are called saprophytes. Those that depend on living plants and animals are called parasites. They can also live as symbionts in association with algae as lichens and with root of higher plants as mycorrhiza.
Reproduction in fungi can take place by vegetative means fragmentation, fission and budding. Asexual reproduction is by spores called conidia or sporangiiospores or zoospores and sexual reproduction is by oospores, ascospores and basidiospores . the various spores are produced by distint structure called footing body.The sexual cycles involve three following steps.
1)fusion of protoplasams between two motile or non motile gametes called plasmogamy.
2)Fusion of two nuclie called karyogamy.
3)meiosis in zygote resulting in haploid spores.
PHYCOMYCETES
Members of phycomycetes are found in aquatic habitats and on decaying wood in moist and damp places or as obligate parasites on plants.The mycelium is aseptate and cenocytic Asexual reproduction takes places by cenocytic.Asexual reproduction takes place by zoospores or by aplanospores. These spores are endogeneously produced in sporangium. A zygospores are formed by fusion of two gametes. These gametes are similar in morphology or disimilar. some common examples are Mucor,Rhizopus and albugo .ASCOMYCETES
BASIDIOMYCETES
Commonly known forms of basidiomycetes are mushrooms, bracketfungi or puffballs. They grow in soil, on logs and trees stumps and in living plant bodies as parasites, eg, rusts and smuts. The mycelium is branched and septate. The asexual spores are generally not found, but vegetative reproduction by fragmentation is common. The sex organs are absent but plasmogamy is brought about by fusion of two vegetative or somatic cells of different strains or gonotypes. The resultant structure is dikaryotic which ultimately gives rise to basidium. Karyogamy and meiosis take place in the basidium producing four basidiospores . the basidio spores are exogeneously produced on the basidiu. The basidia are arranged in fruiting bodies are called basidiocarps.DEUTEROMYCETES
Commonly know as imperfect fungi because only the sexual or vegetative phases on these fungi are known. When the sexual form of these fungi were discovered they were moved in to classes they rightly belong to. It is also possible that the sexual and the vegetative stage have been given one name and the sexual stage another . Later when the linkages were established the fungi were correctly identified and moved out of dueteromycetes.Once the prefect stage of the members were discovered they were often moved to ascomycetes known as conidia.
In this chapter we will study characteristics of kingdom monera,protista,fungi system classification.commonly referred to the plants and animals, kingdom,respectively.
since the dawn of civilization their have been many attempts to classify living organism.it was done instinctively not using criteria that were scientific but borne out of a need to use organism for our use for food, shelter and clothing.Aristotle was the earliest to attempt more scientific basis for classification.He used simple morphological characters to classify plants in to trees,shrubs and herbs.He also divided animals in to two groups, those which had red blood and those that it did not.
In Linnaeus time a TWO KINGDOM System of classification with PLANTAE and ANIMALIA kingdom was developed that included all plants and animals respectively.This wsas used till very recently.This system did not distinguish between the eukaryotes and prokaryotes, unicellular and multicellular organism and photosynthetic and non photosynthetic organism.Classification of organism into plants and animals was easily done to understand, inspite, a large number of the organism did not fall to either category.Hence the two kingdom used for a longtime was found inadequate.A need also felt including, besides gross morphology, other characteristics like cell structure,nature of wall mode of nutrition habitat, methods of reproduction, evolutionary relation ships, etc...Classification system for the living organism have hence, undergone several changes over time .
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