Botany

Euglenа, Amoeba and Chlamydomonas

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Аmоebа:Definition, and Characteristics
Аmоebа is the miсrоsсорiс uniсellulаr рrоtоzоаns. The well-knоwn tyрe sрeсies, Аmоebа рrоteus, is fоund оn deсаying bоttоm vegetаtiоn оf freshwаter streаms аnd роnds. There аre numerоus раrаsitiс аmоebаs. Оf six sрeсies fоund in the humаn аlimentаry trасt, Entаmоebа histоlytiса саuses аmebiс dysentery. Twо relаted free-living generа оf inсreаsing biоmediсаl imроrtаnсe аre Асаnthаmоebа аnd Nаegleriа, strаins оf whiсh hаve been reсоgnized аs diseаse-саusing раrаsites in severаl vertebrаtes, inсluding humаns.
Аmоebаs аre identified by their аbility tо fоrm temроrаry сytорlаsmiс extensiоns саlled рseudороdiа, оr fаlse feet, by meаns оf whiсh they mоve аbоut. This tyрe оf mоvement, саlled аmоebоid mоvement, is соnsidered tо be the mоst рrimitive fоrm оf аnimаl lосоmоtiоn.
Аmоebаs аre used extensively in сell reseаrсh fоr determining the relаtive funсtiоns аnd interасtiоns оf the nuсleus аnd the сytорlаsm. Eасh аmоebа соntаins а smаll mаss оf jellylike сytорlаsm, whiсh is differentiаted intо а thin оuter рlаsmа membrаne, а lаyer оf stiff, сleаr eсtорlаsm just within the рlаsmа membrаne, аnd а сentrаl grаnulаr endорlаsm. The endорlаsm соntаins fооd vасuоles, а grаnulаr nuсleus, аnd а сleаr соntrасtile vасuоle. The аmоebа hаs nо mоuth оr аnus; fооd is tаken in аnd mаteriаl exсreted аt аny роint оn the сell surfасe. During feeding, extensiоns оf сytорlаsm flоw аrоund fооd раrtiсles, surrоunding them аnd fоrming а vасuоle intо whiсh enzymes аre seсreted tо digest the раrtiсles. Оxygen diffuses intо the сell frоm the surrоunding wаter, аnd metаbоliс wаstes diffuse frоm the аmоebа intо the surrоunding wаter. А соntrасtile vасuоle, whiсh remоves exсess wаter frоm the аmоebа, is аbsent in mоst mаrine аnd раrаsitiс sрeсies. Reрrоduсtiоn is аsexuаl (binаry fissiоn).
During аdverse envirоnmentаl рeriоds mаny аmоebаs survive by enсystment. the аmоebа beсоmes сirсulаr, lоses mоst оf its wаter, аnd seсretes а сyst membrаne thаt serves аs а рrоteсtive соvering. When the envirоnment is аgаin suitаble, the envelорe ruрtures, аnd the аmоebа emerges

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Protista:Definition,Characteristics,Classification, and Economic Importance

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Consumer Decomposer Protista
These are also known as Slime Molds because they show the holozoic mode of nutrition. these are also known as Decomposers because they show the saprophytic mode of nutrition. the slime molds were placed in kingdom fungi because some of the characters resemble fungi but due to their unicellular and eukaryotic nature, they are shifted to Protista which is why they are known as protistan fungi.

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Eubacteria: Definition, Characteristics, Nutrition, and Reproduction

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Definition Eubacteria
Eubacteria, or “true” bacteria, are prokaryotic organisms with only one cell. Its cell membrane is made up of glycerol ester lipids and contains lipids. They are distinguished by the absence of a nuclear membrane, a single circular chromosome, and peptidoglycan-based cell walls.

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Bacteria: Nutrition and its Types, Autotrophic Nutrition and Heterotrophic Nutrition

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A. Phototrophs: the bacteria which use light energy as a source of energy are known as photo-Autotrophs. It is of two types
1. Green sulphur bacteria 2. Purple Sulphur bacteria
1. Green sulphur bacteria: these are small nonmotile, rod-shaped bacteria that are anaerobic photoautotrophs. they contain a pigment called Chlorobium chlorophyll also known as Bacterioviridin that is responsible for absorbing light energy. these bacteria use H2S or other reduced inorganic sulphur compounds as electron donors.e,g Chlorobium, etc
2. Purple Sulphur bacteria: These are also autotrophs and their photosynthetic pigments are bacteriochlorophyll a or b. e,g Thiospirillum, and Amoebobacter.

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Bacteria: Definition, Size,Distribution and Classification

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Distribution of Bacteria
Bacteria are found in all-natural ecosystems and have a worldwide distribution. Their distribution is because they can withstand great extremes of temperature, moisture, acidity, and salinity and are adapted to a wide variety of energy sources. They occur in the atmosphere to a height of about six kilometers and on the seafloor five kilometers below the mean sea level. they exist in hot springs and can also survive below freezing points in the Atlantic ice. Bacteria live at the pressure of one atmosphere but they can tolerate the pressure of 3000-6000 atmospheres. some bacteria can live in presence of oxygen while some live without oxygen. the great success of bacteria is due to their small size, rapid reproductive rate, ability to survive under adverse conditions, and metabolic adaptations.

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Lichens: Economic Importance

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Lichen: Definition
Lichens are a small group of curious plants. Lichen represents the permanent association between Algae and Fungi. This association is a symbiotic association, it means both the partners are mutually benefitted. The Algal partner which is associated with the body of the lichen is called Phycobiont and the fungal partner is called Mycobiont.
The Algal partner forms only 1-5% of lichen body (lichen thallus). In the phycobiont, the members which are present belong to Chlorophyceae and BGA. The phycobiont forms food for the fungi and performs photosynthesis. If the phycobiont is GBA, then it is involved in nitrogen fixation such type of lichen which can perform Nitrogen fixation is known as Azotodesmic.
In the mycobiont, the fungal partner belongs to Ascomycetes but in a few cases, it can also be a member of Basidiomycetes. Mycobiont protects algae. It will form a protective covering along phycobiont (Algal partner). Along with that it also helps in the attachment of lichen to a different surface. It also assists with water and mineral absorption.

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Two-kingdom system of classification: Characters, Disadvantages, and Dual Organisms

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Five-kingdom system of classification: Definition and Characters
Hello, dear students today we will discuss the Five-kingdom system of classification, it was R.H. Whittaker in 1969 classified organisms into Kingdom Plantae, Kingdom Animalia, Kingdom Protista, Kingdom Monera, and New one Kingdom Fungi.
Characters for 5 kingdom classification
1. The organism is pro-karyotic or eu-karyotic
2.The organism is unicellular or multicellular
3. The living being is auto-trophic or hetero-trophic, if the living being is hetero-trophic it is three types A. parasitic B. saprophytic C. holozoic
4. Reproduction refers to whether the individual perform asexually, sexually or both
5. Evolutionary relationship describes how a new individual evolved from an older one, how creation took place

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Binomial Nomenclature: Definition, Rules and Advantages

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Tri-Nomial Nomenclature
The Tri-Nomial Nomenclature was given by Lamark. According to this Nomenclature, the name of an organism consists of three words that is why it is called a trinomial system of Nomenclature. The first name is called Generic name, The second name is called Species name or Species epithet and the third name is known as Sub-species for Animals or variety for Plants.

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Taxonomic Aids: Definition, Types, Examples, and Importance

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Herbarium: Definition, Kinds, and Functions
A herbarium is a place for the storage of dried, pressed plant specimens mounted on herbarium sheets. So we can easily be called Herbarium as a storehouse of plants.
A herbarium is a place where plants collected from far and wide are preserved in pressed and dried conditions. they are kept in pigeon holes of almirahs according to an accepted system of classification. The art of Herbarium was started by an Italian taxonomist Luca Ghini (1490-1556). Plant specimens in a dried state have been preserved for over 450 years. Gherardo Cibo obtained the oldest known Herbarium specimen in 1532, which is held in Rome.
Note: The Herbarium specimens are systematically arranged on Bentham and Hooker classification system.

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