The document discusses the history and systems of biological classification. It begins with Linnaeus' two kingdom system distinguishing animals and plants. It then describes Whittaker's five kingdom system comprising Monera, Protista, Fungi, Plantae, and Animalia. Each kingdom is defined by characteristics like cellular organization, nutrition, and whether organisms are prokaryotic or eukaryotic. Key details about the kingdoms of plants, fungi, protists, and bacteria/monera are provided.

1.  History of Classification
 Five kingdom of Classification
 Overview
• Monera
• Protista
• Fungi
• Plantae
• Animalia

2. History of taxonomic concepts

3. Two Kingdoms Classification:
In his Systema Naturae, first published in 1735, Carolus Linnaeus distinguished two kingdoms of living
things: Animalia for animals and Plantae (Vegetabilia) for plants. He classified all living organisms into
two kingdoms – on the basis of nutrition and locomotion (mobility).
Linnaeus placed unicellular protozoans and multicellular animals (metazoans) under animal kingdom
because of their compact body, holozoic nutrition (ingestion of food) and locomotion. All other organisms
were grouped under plant kingdom because of their immobility, spread out appearance and autotrophic
mode of nutrition. Thus, the traditional plant kingdom comprised bacteria, algae, plants and fungi
Demerits or Limitations:
(a) The two kingdom system of classification did not indicate any evolutionary
relationship between plants and animals.
(b) It grouped together the prokaryotes (bacteria, BGA) with other eukaryotes.
(c) It also grouped unicellular and multi-cellular organisms together.
(d)This system did not distinguish the heterotrophic fungi and the autotrophic green
plants.
(e) Dual organisms like Euglena and lichens did not fall into either kingdom.
(f) Slime mould, a type of fungi, can neither be grouped in fungi nor plants.This is
because they are wall less and holozoic in vegetative stage, but develop cell wall in
the reproductive stage.
(g) It did not mention some acellular organisms like viruses and viroids.

4. Algae
Mollusca
Platy
helminthes
Annelida

6. The five-kingdom system In the early days of biology, all organisms were classified
as either plants or animals. In year 1969, Robert H. Whittaker an American
taxonomist, described a five-kingdom classification. The five kingdoms are Monera
(prokaryotes) Protista, Fungi, Plantae and Animalia. His classification is based on
two main criteria the level of organization of the organisms and their method of
nutrition. He recognized two levels of organization prokaryotes (which are without
nucleus) and eukaryotes (which are with nucleus). Eukaryotes are further
subdivided into unicellular and multicellular eukaryotes. The methods of nutrition
were: heterotrophic (which are further subdivided into ingestive and absorptive)
and auto phototrophic. Monera Prokaryotic cellular organization. Protista
Unicellular eukaryotes. Fungi Multicellular eukaryotes which feed heterotrophically
by absorption. Plantae Multicellular eukaryotes which are photoautotrophic,
Animalia Multicellular eukaryotes which feed heterotrophically by ingestion.

8. Cell wall-absent
Cell type-eukaryotic
Nuclear mem-present
Organization-organ
Mode of nut-hetero
Cell wall-non cellulosic
Cell type-eukaryotic
Nuclear mem-present
Organization-organ
Mode of nut-auto
Cell wall-present
Cell type-eukaryotic
Nuclear mem-present
Organization-multicell
Mode of nut-hetero
Cell wall-present
Cell type-eukaryotic
Nuclear mem-present
Organization-unicell
Mode of nut-auto/hetero
Cell wall-absent
Cell type-prokaryotes
Nuclear mem-absent
Organization-unicell
Mode of nut-auto/hetero
Monera
Protista
Fungi
Animalia
Plantae

9. The sexual life cycle in plants alternate between
diploid (sporophyte) and haploid (gametophyte)
phases. Sporophyte literally means spore-plant,
and gametophyte means gamete-plant. The
haploid gametophytic body produces gametes by
mitosis whereas the diploid sporophytic phase
produces meiospores (sexual spores) by the
process of meiosis. The diploid phase produces
the haploid phase by meiosis; the haploid
gametes then fuse to make a zygote that starts
another diploid phase. Three distinct versions of a
generalized sexual life cycle occur among plants:

10. Plantae
Algae Bryophyta Pteridophyta Gymnosperm Angiosperm

11. The kingdom plantae are multicellular eukaryotes with photosynthetic nutrition. Cells typically have
cellulose wall, vacuole, plastids and several photosynthetic pigments which always include chlorophyll a. It
can be broadly divided into:
Cryptogamae (plant without seeds): Algae (Thallophyta), Bryophytes and Pteridophytes.
Phanerogamae (plant with seeds): Gymnosperm and Angiosperm
Bryophyta, pteridophyta, gymnosperm and angiosperm are termed as the land plants or embryophytes.
One major innovation of land plants was the evolution of the embryo. The embryo is defined as an
immature sporophyte. Land plants can be vascular (or tracheophyta) and non-vascular. During the early
evolution of land plants, nonvascular land plants diverged before the vascular plants. Non-vascular plants
are often informally called bryophytes (from the Greek bryon, moss, and phyton, plant). Bryophytes include
the liverworts, hornworts and mosses. The terms bryophyta and bryophyte are not synonymous. Bryophyta
is the formal taxonomic name for the phylum that consists solely of mosses.
The sexual life cycle in plants alternate between diploid (sporophyte) and haploid (gametophyte) phases.
Sporophyte literally means spore-plant, and gametophyte means gamete-plant. The haploid gametophytic
body produces gametes by mitosis whereas the diploid sporophytic phase produces meiospores (sexual
spores) by the process of meiosis. The diploid phase produces the haploid phase by meiosis; the haploid
gametes then fuse to make a zygote that starts another diploid phase. Three distinct versions of a
generalized sexual life cycle occur among plants:

12. In haplontic life cycle, diploid sporophytic
phase is represented only by the one-celled
zygote. There are no free living sporophytes.
The dominant, photosynthetic phase is the
free-living gametophyte. The haploid
gametophyte produce gametes by mitosis.
Fusion of gametes (termed fertilization or
syngamy) forms diploid zygote. Meiosis occurs
in the zygote (zygotic meiosis) which results in
the formation of haploid meiospores. These
spores in turn, germinate and divide by
mitosis to form a haploid gametophyte body
once again. Most green algae such as Volvox,
Spirogyra and some species of
Chlamydomonas represent this pattern of life
Haplontic life cycle

13. Diploid
2n
Gametes
n
Zygote
Diplontic life cycle In diplontic life cycle, the zygote
divides mitotically to produce a multicellular diploid
individual. The diploid phase is the dominant,
photosynthetic and independent phase. Certain cells
of a multicellular diploid phase undergo meiosis to
make gametes, not meiospores. Because meiosis
produces gametes directly, it is called gametic
meiosis. Fusion of gametes restores the diploid
phase. This pattern of life cycle is not common in
plants. Some brown algae such as Sargassum,
Fucus follow this pattern of life cycle
Diplontic life
Fertilization

14. Sporophyte
2n
Spores(n)
Gametophyte
n
Gametes m/f
n
Zygote
2n
Fertilization
meiosis
Haplo-diplontic life cycle In the
haplo-diplontic (also called
diplobiontic) life cycle, diploid
sporophyte produces haploid spores
(meiospores) by the process of
meiosis. Because meiosis produces
spores directly, it is called sporic
meiosis. The meiospores germinate
and grow by mitosis into the
multicellular haploid gametophytic
phase of the cycle. The gametophyte
bodies produce gametes by mitosis.
Fusion of gametes gives diploid
zygote.
Haplo-diplontic
life cycle

16. Algae are chlorophyll-bearing thalloid organisms. However, term algae is used for both
prokaryotic as well as eukaryotic photosynthetic thalloid organisms. The eukaryotic algae
are part of plantae and photosynthetic protists The algae belongs to plantae can be
described as non-vascular (no xylem and phloem), non-embryophytic (no embryo
development) and thalloid (body not differentiated into root, stem and leaf) plants.
Algae includes three main groups of algae; green algae, red algae and brown algae,
distinguished by the following characteristics:
• Primary photosynthetic pigments;
• Storage product,
• Cell wall composition,
• Type and location of flagella.
=

17. Green algae (Chlorophyceae)
Habitat - Mostly fresh water, some marine and terrestrial
Photosynthetic pigments - Chlorophylls a and b, carotenoids.
Cell wall components - Cellulose (major component)
Stored food - Starch (stored inside the plastids).
Flagella - Most with two flagella per cell.
Asexual reproduction - Usually reproduce vegetatively by fragmentation or
by formation of mitospores.
Sexual reproduction- . The sexual reproduction shows considerable
variation in the type and formation of gametes and it may be isogamous,
anisogamous or oogamous.
Example Chlamydomonas, Volvox, Ulothrix, Spirogyra, Chara and Ulva
(Sea lettuce).