Need for Classification

It is not possible for anyone to study all the organisms. But if they are grouped in some convention way, the study would become easier. Classification allows us to understand diversity better

Necessity for classification

Classification helps us to identify the living organisms easily.

It helps us to learn about different kinds of plants and animals, theirfeatures, similarities and differences.

It enable us to understand how complex organisms evolve from simpleones.

R_H. Whittaker (1920 – 1980) was an American plant ecologist.

 In 1969 he classified the organisms into five kingdoms. This classificationhas been accepted by all scientists.

About 9,000 species are identified under Kingdom Monera. The number ofspecies in Kingdom Protista is about 59,950

The number of species under Fungi is about 100,000 The number of speciesidentified under the Kingdom Plantae is about 289,640 The total number ofspecies identified under Animalia is about 1,170,000.

 The Five Kindoms are Monera, Protista, Fungi, Plantae and Animalia.

Kingdom of Monera

General features `

• The kingdom Monera comprises all the bacteria and the cyanobactreia.
• They are Primitive unicellular single celled organisms.
• Theydonothavea true nucleus(Prokaryotic)
• Their mode of nutrition is autotrophic or heterolrophic.
• They cause diseases like diphtheria,pneumonia, tuberculosis, leprosy etc.
• They are also used in manufacture of antibiotics to cure many diseases.

Discovery of Bacteria

• In 1675 Anton Von Leewvenhoek, a Dutch scientist, discovered bacteria.
• Anton Von Leewvenhoekis called as the father of bacteriology.
• Bacteria are considered as the first formed organisms in the world,

Shape of Bacteria

The shape of bacteria varies in different species. The important shapes are

1. rod

B.spherical

C.Comma

1. Spiral.

Beneficial bacteria

The average human gut contains about l kg of bacteria. Their presence is essential for normal health.

Harmful Bacteria

 Bacteria cause many diseases in plants and human beings

Kingdom of Protista

General features

• The kingdom Protista includes unicellular eukaryotes.
• Animals and plants of protista live in sea as well as in fresh water. Some are parasites. Through they are single celled, they have the capacity of performing all the body activities
• They have nucleus enclosed by a nuclear membrane (eukaryotic).
• Some of them posses chloroplast and make their food by photosynthesis.

e.g. Euglena

There are two main groups of protista.

• Plant like protista called photosynthetic and are commonly known as Micro-algae. They can be seen only under microscope. They occur as single cells or filaments or colonies. eg. Chlamydomonas, Volvox etc.
• Algae are autotrophs. `
• Animal like protista are often called protozoans. Protozoans include Amoeba and Paramecium like animals.
• The Paramecium, which consists of cilia, belongs to class ciliate. Amoeba which consists of pseudopodia belongs to class Sarcodina.
• All unicellular plants are collectively called phytoplanktons and unicellular animals as zooplanktons_
• Euglena, a protozoan possesses chloroplast and make their food by photosynthesis. It has two modes of nutrition. In the presence of sunlightit is heterotrophic. This mode of nutrition is known as myxotrophic and hence they form a border line between plants and animals.

Kingdom of Fungi

General features

• This kingdom Fungi includes Yeast,moulds,mushroorns (Kaalaan),toadstools, puffballs and Penicillium
• Fungi are eukaryotic, and mostly multicellular
• Their mode of nutrition is heterotrophic(obtain their nutrients from other organisms)
• since they lack the green pigment chlorophyll.
• They have cell walls, made of a tough complex sugar called chitin
• Fungi act either as decomposers(decay-causing organisms) or as parasites(live in other organisms)in nature
• Mould fungi grow stale bread, cheese, fruit or other food.
• Penicillium is a fungus.
• Penicillin is also known as “the queen of drugs”.

Kingdom of Plantae

General features

• It includes all multi – cellular plants of land and water.
• Kingdom Plantae includes.

(i)Algae (Multicellular)

1. Larninaria, spirogyra, chara

(ii)Bryophytes

1. Riccia, moss

(iii)Pteridophytes

1. Ferns

(iv)Gymnosperms

1. Cycas, pinus

(v)Angiosperms

1. Grass, coconut mango, neem (veppamaram)

• Plantae are multicellular eukaryotes.
• The plant cells have an outside cell wall that contain cellulose.
• They show various modes of nutrition them are autotrophs sincethey have chlorophyll.

Some plants are heterotrophs

1. Cuscuta is a parasite

• Nepenthes and Drosera are insectivorous plants.

More to Know

• Kingdom Plan includes
• Bryophyia – 24,000 species
• Pteridophyta – 10,000 species
• Gymnosperms – 640 species
• Angiosperms – 255,000 species

Kingdom of Animalia

General features

• This kingdom includes all multicellular eukaryotic animals.
• All animals show heterotrophic mode of nutrition. They directly or indirectly depend on plants for their basic requirements particularly the
• They form the consumers of an ecosystem.
• The cells are without cell wall.
• They have contractibility of the muscle cells
• They have well-developed control and coordination mechanisms.
• They can transmit impulses due to the presence of nerve cells.
• Some groups of animals are parasites e.g. tapeworms and roundworms.
• Most members of can move from place to place. However ,some animals such as adult sponges and corals are permanently attached to a surface
• KingdomAnimalia includes the following phyla.

Binomial Nomenclature

History of classification ,

• Aristotle categorized organisms into plants and animals
• Hippocrates, the Father of Medicine,listed organisms with medicinalvalue.
• Joh Ray introduced the term species
• Carolus Linnaeus organized a simple naming system for plants. So, he is known as Father of Taxonomy

Basic Principles of  Binomial Nomenclature

• Scientific names must be either Latin or Latized
• The name must of the genus begins with a capital letter.
• The name of the species begins with a small letter.
• When printed, the scientific name is given in italics.
• When written by hand, name should be underlined

ANIMAL KINGDOM

Introduction

• Animals originated approximetely 600 million year ago. More than 2 million existing varieties of animals have been identified. Of these more than 12,72,000 are invertebrates and fewer than 62,000 species are vertebrates.

Taxonomy

• The branch of biology dealing with identification, description, nomenclature and classification is called taxonomy.
• Aristotle, the father of Zoology was the first to classify animals based on their similarities and differences.
• Carl Linnaeus, the Swedish Botanist is regarded as the father of modern taxonomy

Levels of classification

• Linnaeus classified organisms into kingdom, phylum, class, order, family,genus and species.

Criteria for classification

1. Grade of organization
2. Germ layers
3. Symmetry
4. Asymmetrical (e.g. Amoeba)
5. Radially symmetrical (e.g. Hybra)
6. Bilaterally symmetrical(e.g Earth worm)
7. Coelom – the space between the body wall and digestive tract is calledcoelom.
8. Body temperature

a.Poikilothermic animals-Whose  body temperature varies with that of environment .Fish, frog)

1. Homeothermic animals – whose body temperature always remainsconstant. (e.g. Birds, man)

Animals are classified into two major groups, namely invertebrates andvertebrates based on the absence or presence of back bone (Vertebral column)

Invertebrates

1. Phylum Protozoa (e.g. Amoeba)
2. Phylum Porifera (e.g. Sponges)
3. Phylum Coelenterata (e. g. Hydra)
4. Phylum Platyhelminthes (e.g. Tape worm) Pl
5. Phylum Aschelminthes (e.g. Ascaris)
6. Phylum Anneljda (e.g. Earth worm)
7. Phylum Arthropoda ‘(e.g. Cockroach)
8. Phylum Mollusca (e.g. Snail) and
9. Phylum Echinodermata (e.g. Star fish)

Phylum Protozoa

• These are generally unicellular microscopic animals. Locomotion takes place by cilia, flagella or pseudopodia.

Phylum Porifera

• These are non-motile marine animals a solid support such as rocks or shells.
• They possess an internal skeleton made up of calcareous or silicious spicules.

Phylum Coelenterata

• There is a distinct body cavity called coelenterons

Phylum Platyhelminthes(flat worms)

• These are triploblastic,bilaterally symmetrical and acoelomate animals
• They are mostly hermaphrodites(i.e male and female sex organs are present in the  same individual

Phylum Aschelminthes (round or thread worms)

• The body is cylindrical unsegmented.
• Sexes are separate and fertilization is internal.
• These are familiar as parasitic worms causing elephantiasis (filarial worm) and ascariasis (ascaris)

Phylum Annelida

• Earthworms and leeches are familiar examples of annelids
• They exhibit cephalisation (formation of a distinct head)and metamerism (Segmental repetition of identical organs)

Hirudin

• Hirudin is a naturally occurring protein in the salivary glands of Leeches that has a blood anticoagulant property
• Hence blood fails to clot ensuring continuous flow of blood
• This property is widely used in the field of medicine

Phylum Arthropoda

• Arthropods are the largest group of organisms and insects are the most successful group of animals
• They possess compound eyes
• Insects form one of the most successful groups of animals

Phylum Mollusca

• Body is soft,unsegmented and without appendages
• Respiration is usually by gills called ctenidia

Phylum Echinodermata

• Body is covered by calcareous spines. Water vascular system is a characteristic feature of this group

Biodiversity of India

• India is endowed with an immense variety of plants and animals. It is a home to 2000 species of fishes, 182 species of amphibians, 453 Species of reptiles, 1200 species of birds and 350 species of mammals.
• In ranks within in the top 10 countries in the world in the biodiversity of vertebrates.

Vertebrates

Vertebrates have a true vertebral column and internal skeleton. These are coelomate, triploblastic animals with a notochord nerve chord.

Vertebrates are classified into five classes as follows

1.Class Pisces

2.ClassAmphibia

3.ClassReptilia

4.Clss Aves and

5.Class Mammalia

1. Class Pisces

• These are aquatic animals and their skin is covered with scales
• The body is streamlined respiration is by gills.

Migration in fishes

Types of horizontal migration

1. Anadromous Migration – Fishes live in the ocean mostly and bred in fresh water
2. Catadromous Migration Fishes live in fresh breed in theocean
3. Amphidromous Migration-fishes move between fresh and salt water their life cycle but not for breeding

Class Amphibia

• Amphibians are cold blooded vertebrates which can live on land as well as in water(dual life)
• Amphibians are clod indicator of environmental changes.
• They breathe partially through their skin which makes them sensitive toradiation, pollution and habitat destruction.
• The stone fish may be the highly poisonous fish in the world.
• The drug derived from the extract of Poison arrow frog (Epipedobatestricolor) works as a powerful painkiller.

Class Reptilia

These are creeping or crawling terrestrial animals and their body is covered with dryskin or epidermal scales.

Superlatives

• The slowest reptile – Giant tortoises of Galapagos Islands
• The fastest reptile Spiny tailed Iguana of Costa Rica
• World’s fastest snake – The black mamba of Africa
• The World’s longest snake A reticulated phthon
• Largest poisonous snake – King Cobra
• Smallest reptile – Gecko
• Largest reptile –Komodo dragon

Class Aves                          

Birds are worm blooded oviparous which lay cledoic eggs (with shell) with large amount of yolk (reserve food)

Class Mammalia

• Mammals are higher chordates characterized by a presence of milkproducing glands (mammary glands)
• Heterodont dentition
• Diaphragm (muscle which separate ‘thorax and abdomen) pulmonaryrespiration (lungs), internal fertilization and viviparity are other salient features.

Echolocation in Bats

• Echolocation is also called bio sonar which is used by several animals like bats.