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Biological Classification

• Aristotle made the first attempt to classify organisms.

• Aristotle classified plants based on morphology into herbs, shrubs, and trees.

• Animals were classified by Aristotle based on the presence or absence of red blood.

• Carolus Linnaeus is known as the father of taxonomy.

• Carolus Linnaeus proposed the two-kingdom classification, dividing living organisms into Kingdom Plantae and Kingdom Animalia.

• Drawbacks of the classification:

  • Did not distinguish between eukaryotes and prokaryotes.
  • Did not distinguish between unicellular and multicellular organisms.
  • Failed to differentiate between autotrophic and heterotrophic organisms.
  • Many organisms did not fit into either category.
  • Placed similar organisms in different groups and vice-versa.

• R.H. Whittaker proposed the five-kingdom classification in 1969, which includes Monera, Protista, Fungi, Plantae, and Animalia.

• Criteria for the five-kingdom classification include:

  • Cell structure
  • Body organization
  • Mode of nutrition
  • Reproduction
  • Phylogenetic relationship

Kingdom Monera

• General characteristics include:
  • Prokaryotic: Lacks a well-defined nucleus and membrane-bound cell organelles.
  • Non-cellulosic cell wall composed of polysaccharide and amino acids.
  • Unicellular organization.
  • Autotrophic (chemosynthetic or photosynthetic) or heterotrophic (saprophytic/parasitic) nutrition. - Bacteria and Mycoplasma are members.
• Bacteria:
  • Are the sole members of kingdom monera.
  • They are the most abundant microorganisms, found almost everywhere.
  • They live in extreme habitats.
  • Their structure is simple but their behavior is complex.
  • They exhibit extensive metabolic diversity.
  • The reproduction processes of bacteria:
    • They are mainly reproduced by fission.
    • They produce spores under unfavorable conditions.
    • They perform a primitive type of sexual reproduction involving DNA transfer from one bacterium to another.
• Bacteria is classified on the basis of shape
  • Coccus: spherical
  • Bacillus: rod-shaped
  • Vibrium: comma-shaped
  • Spirillum: spiral-shaped

Archaebacteria

• Archaebacteria survive in extreme conditions due to their unique cell wall structure.
  • Halophiles live in extreme salty areas.
  • Thermoacidophiles live in hot springs.
  • Methanogens live in marshy areas and in the gut of ruminant animals, producing methane (biogas) from dung.

Eubacteria

• Eubacteria (true bacteria) have a rigid cell wall, and if motile, they possess a flagellum.
  • Cyanobacteria (blue-green algae): Examples include Nostoc and Anabaena.
    • They are unicellular, colonial, or filamentous.
    • They can be found in fresh water, marine, and terrestrial environments
    • Colonies are covered by a mucilaginous sheath.
    • They can fix atmospheric nitrogen in specialized cells called heterocysts.
    • Algal bloom: it is caused due to the overproduction of cyanobacteria, and it leads to water pollution

Chemosynthetic Bacteria

• Chemosynthetic bacteria prepare food by utilizing chemical energy released through oxidation. They play a role in the recycling of minerals like sulfur and phosphorus

Heterotrophic Bacteria

• They are abundant in nature and important decomposers.
  • They are used for making curd from milk, producing antibiotics, and recycling minerals.
  • Some can be pathogens causing diseases like cholera, typhoid, tetanus, pneumonia, and citrus canker in plants.

Mycoplasma

• Mycoplasma are the smallest living organisms, capable of surviving without oxygen.
  • They lack a cell wall and are pathogenic.

Kingdom Protista

• General characteristics of kingdom Protista
  • Eukaryotic with a well defined nucleus and membrane bound cell organelles.
  • Unicellular organization.
  • Typically aquatic.
  • Forms link with plants, animals, and fungi
  • Cell wall may be present in some.
  • Photosynthetic and heterotrophic modes of nutrition.
  • Reproduces sexually and asexually through cell fusion and zygote formation.

Classification of kingdom

    - Chrysophytes includes diatoms & Golden algae (Desmids)
       - They are found in aquatic habitats such as freshwater and marine water
       - Are Photosynthetic
       - Are microscopic planktons that float freely on water
          
    -Diatoms:
       - Are the chief producers in the ocean.
       - Their cell walls are embedded with indestructible silica.
       - Their cell walls form two overlapping shells that fit like a soap box.
       - Diatomaceous earth: made up accumulation of cell wall deposits of diatoms, and are rich with soil that is used in polishing, and for the filtration of oils & syrups
    - Dinoflagellate:
        - They are commonly found in marine environment
        - Are Photosynthetic
        - The color of dinoflagellates can appear yellow, green, brown, blue, or red, depending on the primary pigment present in their cell wall.
        Cell walls have stiff cellulose plates on the outer surface along with 2 flagella
        Red tide: The rapid multiplication of red dinoflagellates makes the 
        sea appear red, and it releases toxins that may even kill fish & other marine animals.
    - Euglenoids:
        - They are commonly found in freshwater

Photosynthetic in the presence of sunlight and act as heterotrophs in the absence of light Instead of a cell wall, a protein-rich layer called pellicle that is present, which makes their body flexible - Has 2 flagella one short and one long. - Its pigments are similar to the those that are found in the higher plants

Slime moulds

• They are Saprophytic and live & take food from dead organic matter

  • The body move along decaying twigs & leaves of forest -They form an aggregation called plasmodium under suitable conditions,
  • Plasmodium differentiate & form fruiting bodies which bear spores at their tip during unfavourable condition
  • Has extremely resistant spores that can survive for many years and that Spores will gets dispersed by air currents

Protozoans

• They are primitive relatives of animals

  • They are Heterotrophs (predator or parasites) that can survive by taking living organisms
  • The are classified into the following four major groups :-
    • Amoeboid protozoans :-eg., Amoeba, Entamoeba
      • They can grow in fresh water, sea water, or moist soil, while some are parasites
      • They Move & capture prey by putting out pseudopodia and marine organisms
      • Marine forms have silica shells on their surface.
    • Flagellated protozoan :- such as Trypanosoma that causes sleeping sickness, and are Free living or parasitic protozoans with flagella
    • Ciliated protozoan :- eg., Paramoeciu, and are mostly Aquatic organisms that have thousands of cilia
      • A cavity (gullet) opens outside the cell surface and used for the co-ordinated movement of rows of cilia to direct Water with food into the gullet
    • Sporozoans :- They have an infectious spore like stage in their life cycle such like Plasmodium

Kingdom Fungi

• Kingdom Fungi are cosmopolitan that grows in warm & humid places

• They Multicellular and exceptions are unicellular (Yeast) that are filamentous

• The Hyphae (fungal body) structure is made of long slender thread like structures that form Network is called Mycelium

• The continuous tubes formed by Hyphae that have multinucliated cytoplasms is called Coenocytic hyphae (Aseptate hyphae) Septate hyhae is the hypha having septa/cross walls

• Their cell wall is composed of chitin & polysaccharides

  • Types of Fungi:
    • Saprophytic fungi – heterotrophic that is used to live and absorb nutrients from dead substrates.
    • Parasitic fungi – Live and absorb nutrients from living plants & animals.
    • Lichen -Symbiotic association between algae and fungus.

• Mycorrhiza -Symbiotic association between fungus and roots of higher plants like pinus

Uses of fungi:

- Edible (Mushroom), Used to make bread and Yeast (unicellular fungus).
- Source of Antibiotics (Penicillium)
 - Disadvantages Of Fungi

Create harm by spoiling food and destroying the timber - Disease caused by: Puccinia (cause wheat rust). - Ustilago: cause smut disease - Asperegillus: (Aspergillosis in man) - Candida: cause (candidiasis in man) - Reproduction - vegetative: By fragmentation, fission and budding - Asexual- By spores (conidia, sporangiospores or zoospores)

sexual reproductions

  - PlasmaGamy- Fusion of protoplasm between two non-motile or motile gametes karyogamy = fusion of nuclei
    - Meiosis - Zygote undergoes meiosis to form haploid spores. Spores germinate
    - Dikaryophase – Phase between plasmogamy and karyogamy. Dikaryotic stage
                    (n+n ie., 2 nuclei per cell). Such condition is called Dikaryon. This stage occur in
                     Ascomycetes &Basidiomycete. Later parental nuclei fuse  and cell become diploid.
    - Sexual spores – Oospores, Ascospores and Basidiospores

Classification Of Kingdom Fungi

Phycomycete - aquatic habitat, decaying wood, moist & damp or on plants as parasites
   - Mycelia is aseptate & coenocytic, an Asexual production by zoospores or aplanospores
   - Sexual reproduction - 2 gametes that fuse to form zygospore
   - the gamete structure is isogamous or dissimilar (Anisogamous or Oogamous)
Asomycete - saprophytes, decomposers, parasites or coprophilous
   - Branched & septate mycelium
   - Asexual reproduction- is exogenously created by condidia with germinate to develop myceilium
   - Sexual reproduction- has ascospores which is arranged in ascocarp
           - Has Penicillum yeast aspergillus claviceps
Basidiomycete - grow in soil, and are on logs, is parasitic on tree stumps
        - Branched AND septate mycelium
       - A sexual reproduction-Generally not found
       - Vegetative fragmentation reproduction occurs
        - Sexual reproduction has basidiospores for exogenously production
        - ex- Agoricus used to treat smut and rust fungus
Dueteromycete - asexual reproduction by conidia
   - septate & branches mycelium
   - there are decomposers of litter that help in mineral cycling

Kingdom Plantae

• General characteristics of kingdom Plantae
  • Eukaryotic, Multicellular, photosynthetic organisms
  • The Cell walls are made up of cellulose
  • They are Some Partially heterotrophic – Insectivorus plants (Bladder wort & venus fly Trap) & Parsite (Cuscuta) have Generation alternation
  • Alternation of generation - Diploid sporophytic phase in the life cycle alternate with Haploid gametophytic phase

Kingdom Animalia

• Characteristics of Kingdom Animalia:

  • Eukaryotic, multicellular, heterotrophic organisms.
  • Lack cell wall.
  • Holozoic nutrition through ingestion of food.
  • Digestion of food in an internal cavity.
  • Glycogen or fat serve as food reserves
  • Sensory and neuromotor mechanisms enable locomotion.
  • Definite growth pattern into adults with specific shapes and sizes.
  • Sexual reproduction through copulation of male & female, followed by embryological development.

Virus

• Virus are non-cellular organisms that has crystalline structure outside the living cell
• They are non living or living
  • in open environment the dead
  • When infected the body the replicate with their machinery thus killing host from its replacate
• Genetic material of virus is infectious which comprises with DNA/RNA (nucleoprotein)
  • Genetic material such as the capsid of capsomeres is present in the virus that of infect plants contain single starnded RNA
• The viruses that infect animals have either single / double stranded RNA or double stranded DNA.
• There are are obligate parasite
• Scientists and their contribution on viruses includes:;
  • D. J. Iwanowsky (1892) - Recognized certain microbes smaller than bacteria that the are able cause the tobacco mosaic disease - M.W. Beijerineck established Tobacco extracts is able cause the tobacco and called as virus
  • W.M. Stanley Established Virus has crystals

Virus Types

 - Bacteriophage (DNA Is genetic material)

Causes Diseases (Fever, AIDS TB) in plants (mosaic disease leaf curling and rolling)

Viroids

  - Discovery by T.O. Diener
   - They are smaller than a viral component containing the ribonucleic composition
    - Lacks the protein coat to make potato tuber spindle
  - Prions
  - Consists of abnorminal protein structure from mad cow

Lichens

• Lichens have Symbotic relations with both algae & fungus and has
• algal component of phycobiont
• Fungal componetnt -Mycobiont Algae are able supply food whereas water will able supply the mineral water for their growth

Plant Kingdom

Classification Systems

• Artificial systems : equal weightage is given on vegetable & sexual character
• Numerical system: computer will assign the code & analyize character with equal importance
• Natural system : internal & external character with embryology will be used
  • Cytotaxonomy- cytological character, chromosal system, &
  • Chemotaxonomy system for the utilization of the chemical constituent

Division of Algae and main character of usage

• They Live in Aquatic freshwater, and chlorophyll bears Thallus - plant body
  • Occurs in Moist stone, water

Reproduction in Vegetative

 - Fragmentation asexual spore (zoospores) - flagellated /motile spore by Fusion of two gametes.

    - Economic Importance

Plant Division

Algae

Types of Algae - Chloraphyceae (sea, green organism) - They are photosynthetic and bear chlorophyll has the thalloid plant has cell walls which is made of an inner cellulose and outer pectose rigid

• Asexual repro -zoospore, 2 to 8 apical equal flagella a example is :Chlamydomonas
  • Phaepoptyceacae (brown Algae)
    • simple branch-like structure filament and filament as height
• chlorophyll C Fucoxathine (xanthpholl) is the pigment - Alging is the cellulose material and cell covers this - -holdfast, Stipe leaf - -Zoosporas are Pear shaped and the gamates and zoospores are unequal
  • Ex :Dikyoa laminaria
    • rhodo phyceae (red algac)
    • Mulitcellular -compalex body -Major - chlorophyll a and d- phycoerythrin -Food reserved floridan starch

Bryophytes

- The thalli have to grow towards it and need to be humified for plant and animals and have no root system
      - dominant phase

       ### main life cycle

Has gametophyte that has an antheridium for male - male is Antherzoid (Zoid for male gametes can release water) - Archegonium female ( single egg or female gamete) sporophyte with little living sporophytete

Pteridophytes

• These plants has a diploid sporophyte and Leaves are micro or microphytic
• Sporo phytes (spore bearing plants and lower part of the sporangial - main structure: main structure in Salingalla
  • -Spores have to form together and call thallophytes (photosynthetic, free living) H20 essential for transer of the male gamete to the egg is present of sporphyllis
  • Homosporous and Heterosporous Prepared by N.K

Gymnosperms Main Characteristics

• Seeds are naked, not covered with an ovary wall. • Are with medium sized tree to tall tree including gigant red tree •Tap root system is present and can be used to form symbiotic relation with Mycorrhiza • Stem is unbranchcyled whereas leave can be simple of compound • Thick cuticle to prevent water loss in the plant which has reproductive structure that helps from production microspore-megasporess • The seeds undergo different stages where the pollen is releases from microsporongy • In Pllination ,the megasporangium consist of tissue that contains cellulose membrane • It consists of 24 life stages • It gives the angiosperm