This document discusses the major systems of biological classification that have been proposed over time. It begins by outlining Linnaeus' original two kingdom system (plants and animals), followed by Haeckel's three kingdom system (adding protists), Copeland's four kingdom system (splitting protists and adding monera), and Whittaker's influential five kingdom system (monera, protista, fungi, plants, animals). It then provides characteristics of each kingdom in Whittaker's five kingdom system and compares their key attributes.

2. Kingdom Systems of Classification Proposed by
1. Two Kingdom System
Carolus Linnaeus (Kingdom Plantae and
Kingdom Animalia)
2. Three Kingdom System
Ernst Haeckel (Kingdom Plantae, Kingdom
Animalia, Kingdom Protista)
3. Four Kingdom System
Copeland (Kingdom Metaphyta (= Plantae),
Kingdom Metazoa (= Animalia), Kingdom
Protozoa (= Protista), Kingdom Monera)
4. Five Kingdom System
Robert Whittaker (Kingdom Monera, Kingdom
Protista, Kingdom Fungi, Kingdom Plantae,
Kingdom Animalia)

3. 1.Complexity of cell structure: Prokaryotes and Eukaryotes are two main types. The
only kingdom encompassing all prokaryotes is Monera.
2.Complexity of body organization: There are two main
types, Unicellular and Multicellular. The only kingdom encompassing all unicellular
organisms is Protista.
3.Mode of nutrition: There are two main modes, Autotrophic and Heterotrophic. The
kingdom primarily comprising all autotrophs is Plantae.
4.Ecological role: There are two main roles played by the
heterotrophs, Decomposers , and Consumers. Kingdom Animalia encompasses the
consumers, and kingdom Fungi encompasses all decomposers.
5.Phylogenetic relationship: Evolution has been one of the backbones of the Five
Kingdom System of classification.

10. Character Monera Protista Fungi Plantae Animalia
Nucleus Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic
Nuclear
membrane
Absent Present Present Present Present
Mitochondria Absent Present Present Present Present
Plastid Absent
Present for some
forms
Absent Present Absent
Motility
By flagella, gliding, or
some non-motile
By flagella, cilia,
pseudopodia,
some are non-
motile
Non-motile
Non-motile in
higher forms
Present in
various modes
Nutrition
Photoautotrophic,
Chemoautotrophic,
Heterotrophic,
Saprobiotic, Parasitic
Photoautotrophic,
Heterotrophic
Saprobiotic,
Parasitic
Photoautotrophic Heterotrophic
Multicellularity Absent Absent Present Present Present

11.  Examples- Bacteria, Cyanobacteria, Mycoplasma, and Archaea.
 Features of Kingdom Monera
• Organisms belonging to Kingdom Monera are unicellular and prokaryotic.
• These organisms are microscopic and occur everywhere.
• They do not have a well-defined nucleus.
• There is no presence of membrane-bound organelles like endoplasmic reticulum, chloroplasts, mitochondria, or
Golgi complex.
• Some organisms have a cell wall, while other organisms do not.
• The cell wall of monera is usually built of protein and polysaccharide compounds.
• Organisms are heterotrophic or autotrophic.
• While heterotrophic bacteria can be either a saprophyte or a parasite, autotrophic bacteria can be photosynthetic or
chemosynthetic.
• These organisms are known to reproduce by the asexual method of binary fission.
• Respiration may be aerobic or anaerobic.
(a) Obligate aerobes are those which cannot survive without oxygen. Rhodospirillum, Bacillus subtilis.
(b) Obligate anaerobes are those which cannot survive in oxygen. Clostridium botulinum.

12.  They can be categorized into four different kinds based on the shape they form.
Coccus/ Cocci- These bacteria are known to have a spherical shape.
Bacillus/ Bacilli- These bacteria are known to have the shape of a rod.
Vibram/ Vibrio- These bacteria are known to form the shape of a comma.
Spirillum/ Spirilla- These bacteria are spiral-shaped.

13.  The kingdom includes all prokaryotes-
 mycoplasma,
 bacteria,
 actinomycetes
 cyanobacteria.
 Reproduction is asexual except for gene recombination.
 Flagella may be present and are single-stranded.
 Example- Blue-green algae, Bacteria, etc.
 Most primitive prokaryotes live under hostile conditions like
 Extremely salty areas (halophiles)
 Hot springs (thermoacidophiles)
 Marshy area (methanogens)
 They differ from other bacteria in having different cell wall structures (absence of peptidoglycan).
 Methanogens are present in the gut of several ruminant animals like cows and buffalo, which are responsible
for the production of biogas (methane) from the dung of these animals.

14.  Eubacteria – They are called true bacteria.
 They contain a rigid cell wall; if motiles have a flagellum.
 Cyanobacteria or blue-green algae are gram-positive photosynthetic bacteria.
 They contain chlorophyll and carotenoids.
 They may be unicellular, colonial, filamentous, freshwater, marine, or terrestrial.
 Some have specialized heterocyst cells to perform nitrogen fixation (Nostoc and
Anabaena).
 Chemosynthetic bacteria oxidize inorganic substances like nitrate, nitrite, ammonia,
etc., to produce energy and help recycle nitrogen, phosphorous, sulfur, etc.
 Heterotrophic bacteria are most abundant and act as decomposers.
 They are helpful in the production of curd, antibiotics, and fixing nitrogen in leguminous
plants.
 Some are pathogenic and cause diseases like cholera, typhoid, tetanus, and citrus
canker.

15. Mycoplasma – simplest free-living prokaryotes.
They are also known as PPLO (Pleuropneumonia like organism).
They lack a cell wall and can survive without oxygen.
They cause disease in plants and animals.

16.  Features of Kingdom Protista
• Organisms grouped under Kingdom Protista are unicellular and eukaryotic.
• Sometimes they are simple multicellular eukaryotes.
• They are either autotrophs or heterotrophs.
• Some organisms also have appendages that are also called flagella or cilia. They use these
mechanisms to move around.
• They opt for sexual or asexual modes of reproduction.
• Sexual reproduction occurs through the process of the fusion of cells and the formation of a zygote.
• Common examples of protists include Amoeba, Euglena, Diatoms, Paramoecium, and Plasmodium.
• Protists can have two major groups- the first bear similarity with animal cells because they do not
have cell walls; the second bears similarity to plant cells with cell walls and characteristics similar to
that of algae.
• The Protista Kingdom does not have well-defined boundaries.
• These organisms are mostly aquatic organisms.
• The mode of nutrition is either autotrophic (as in algae and diatoms) or heterotrophic (as in
protozoans). Some forms show mixotrophic nutrition (for example, Euglena).

17.  These organisms show overlapping characteristics of plants and animals.
 The boundaries of this kingdom are not well defined.
a. There are Plant-like Protists, like Diatoms, Dinoflagellates, and Euglenoids.
b. There are Fungus-like Protists, like Slime Moulds.
c. There are Animal-like Protists, like Sarcodina and Mastigophora members.
 Sub-groups of Protists:
1. Chrysophytes
2. Dinoflagellates
3. Euglenoids
4. Slime Moulds
5. Protozoans

18.  The Protista Kingdom can be sub-categorized into the following:
• Chrysophytes: This group consists of diatoms and desmids, or golden algae. These organisms are found
living in either freshwater or marine ecosystems.
• Dinoflagellates: These organisms often appear to be green, yellow, red, blue, or brown, depending on the
color of their cell pigments. These are also marine organisms. However, they conduct photosynthesis.
• Euglenoids: These organisms do not have a cell wall, though there is the presence of a pellicle, which is a
protein-rich layer. Most of these organisms live in either freshwater or motionless water bodies.
• Slime Moulds: These are saprophytes, meaning they feed on dead, decaying, or decomposed material.
When conditions are favorable, they often form Plasmodial Slime Moulds.
• Protozoans: Mostly existing as either predators or parasites, protozoans are heterotrophic. These
organisms can be either amoeboid protozoans, flagellated protozoans, ciliated protozoans, or sporozoans.

19.  Kingdom Fungi consist of eukaryotic, heterotrophic, multicellular organisms.
 Features of Kingdom Fungi
• These organisms are eukaryotic.
• They feed on dead or decaying organic matter. Hence they depend on saprophytic modes of nutrition.
• They have cell walls present in them, which are made of a substance called chitin.
• Fungi can be either unicellular or multicellular; yeast is an example of unicellular, and mushrooms are an example of multicellular.
• They are heterotrophic organisms.
• They can also often be parasitic.
• Reproduction may be vegetative (fragmentation, fission or budding), asexual (conidia, sporangiospores or zoospores) or sexual
reproduction by oospores, ascospore and basidiospores.
• Sexual cycles involves the following steps-
 Plasmogamy, fusion of male and female gametes.
 Karyogamy, fusion of two nuclei.
 Meiosis in zygote to produce haploid spores.
• Examples of fungi include mushrooms, yeast, and aspergillus.
• Fungi are incapable of locomotion. They consist of fine threads known as hyphae. An entire web of hyphae is known as mycelium.
• Fungi are non-green (lacking chlorophyll)

20.  Reserve food material consists of glycogen.
 Some fungi live symbiotic relationships with green or blue-green algae, as in lichens.
 Many fungi cause diseases in animals (like ringworm) and plants (like black stem rust
of wheat, white rust in mustard, and late blight of potato).
 Examples: Yeast, Rhizopus, mushrooms, Aspergillus, and Penicillium.
 Fungi are classified based on reproduction into the following four major classes
Phycomycetes
Ascomycetes
Basidiomycetes
Deuteromycetes

21.  Phycomycetes
• They are found in aquatic habitat and on decaying wood in moist and damp places.
• The mycelium is aseptate and coenocytic.
• Asexual reproduction by zoospores (motile) or aplanospores (non-motile).
• Example- Mucus, Rhizopus, Albugo etc.
 Ascomycetes (The sac fungi)
• They are saprophytic, decomposers, parasitic or coprophilous (growing on dung).
• Mycelium branched and septate; and asexual spores are conidia.
• Sexual spores are called ascospores produced inside the fruiting body called
ascocarps.
 Example- Neurospora, Asperigillus, Claviceps etc.

22.  Basidiomycetes (The club fungi)
• The mycelium is branched and septate.
• Vegetative reproduction is by fragmentation.
• Asexual spores are not found.
• Sexual reproduction is by two vegetative or somatic cells forming basidium.
• Basidiospores are produced in basidium by developing a fruiting body called
basidiocarps.
• Example- Agaricus, Ustilago, Puccinia.
 Deuteromycetes (The fungi imperfect)
• Only vegetative and asexual phase is known.
• Mycelium is septate and branched. Some members are saprophytes or parsites.
• Example- Alternaria, Trichoderma, Colletotrichu.

23. Kingdom Plantae
 Kingdom Plantae can be subdivided into categories based on the absence or presence
of specialized vascular tissue and their various body structures.
 Gymnosperms
 Angiosperms
 Pteridophyta
 Thallophyta
 Bryophyta
 Further classification is based on
(i) whether seeds are present or not, and
(ii) whether seeds are enclosed within fruits or not.
 Features of Kingdom Plantae
• These organisms are all eukaryotic organisms and have chloroplasts.
• They are multicellular.
• They have a cell wall that is highly distinct and made of cellulose.

24. • Plantae Kingdom organisms are not motile.
• These organisms make their food by conducting photosynthesis- Autotrophs.
• Some of them are, however, heterotrophs.
• There is the presence of photosynthetic pigments like chlorophyll and plastids.
• These organisms store food in the form of starch.
• They are primarily photoautotrophic and evolve oxygen during photosynthesis.
• Both sexual and asexual forms of reproduction occur in these organisms.
• Typical examples are flowering plants, ferns, conifers, roses, and more.

26.  Features of Kingdom Animalia
• These organisms are eukaryotic, multicellular and do not have a cell wall.
• There is no presence of photosynthetic pigments.
• These are motile organisms.
• They are heterotrophs in nature, which means they cannot make their own food, and they depend
on other organisms for food.
• The Animalia Kingdom is highly diverse with some organisms being extremely simple in terms of
structure and organisation, and some being specialised with a complex tissue organisation
structure.
• These organisms can produce both sexually or asexually.
• Carbon is stored as fat and glycogen.
• Common examples of the animal kingdom include Chordata- vertebrates like birds, reptiles,
fishes, mammals and amphibians, Mollusca- squid and snails, Arthropoda- insects and
crustaceans and more.

31.  Five kingdom system of classification do not includes Virus, Viroid's and Lichens.
• Viruses are non-cellular organisms having inert crystalline structure outside the living.
• When they enter the living cell, they take over the machinery of living cell to replicate
themselves.
• D. J. Ivanowsky recognized certain microbes as causal organism of mosaic disease of
tobacco.
• In addition to proteins, viruses also contain genetic material that could be DNA or RNA.
• In general, virus that infect plants have single stranded RNA and virus that infect animals
have double stranded DNA.
• Some common diseases caused by virus are common cold, influenza, AIDS, small pox, leaf
rolling and curling.
• Bacteria feeding virus are called Bacteriophage.
• They are usually double stranded DNA viruses.
• The protein coat called capsid is made of small subunits called capsomeres, protects the
nucleic acid. These capsomeres are arranged in helical or polyhedral geometric forms.

32. • Viroids are discovered by T.O.Diener as new infectious agent smaller than virus
causing potato spindle tuber disease.
• They are free RNA without protein coat.
 Lichens are symbiotic association between algae and fungi.
 The algal part is called Phycobiont and fungal parts are called Mycobiont.
 They are good pollution indicator as they do not grow in polluted area.