• Nature of Cells: prokaryotic or eukaryotic• Cellularity: unicellular or multicellular• Level of organization: cellular, tissue, organ and

organ system• Mode of nutrition: autotrophic or heterotrophic

Classification and Evolution

Biodiversity• Biodiversity is the term used for the various

forms of life found in a given area.

• These life forms depends on each other andon the environment and results in a stablecommunity.

• Human also is the part of this biodiversity.

• It is estimated that there is about10,000,000 species on this planet, we knowonly about 20,00,000 species.

Hierarchy of classification

• Ernst Haeckel, Robert Whittaker, Carl Woesehave tried to classify all living organisms intobroad categories.

• R. Whittaker proposed five kingdom systemwhich is widely used. This kingdom includesMonera, Protista, Fungi, plantae and Animalia.

• Carl Woese divided Monera intoArchaebacteria and Eubacteria.

Further classification

Further classification is done by naming the subgroups at Various levels as given:

Kingdom→Phyllum\Divison→Class→Order→Family→Genus→Species

•Kingdom Monera•Kingdom Protista•Kingdom Fungi•Kingdom Plantae•Kingdom Animalia

Kingdom: Monera• Unicellular organisms.

• Nucleus and cell organelles are absent.

• May or may not have cell wall.

• Autotrophic or heterotrophic.

• Able of nitrogen fixation.

• Reproduce by asexual methods.

• Bacteria, cyanobacteriaand mycoplasma

Kingdom: Protista

• Unicellular organisms.

• A well defined nucleus and cell organelles are present.

• They may be autotrophic or heterotrophic.

• Some of these organisms have appendages like cilia and flagella for movement.

• They reproduce by both sexual and asexual methods.

• Diatoms, protozoans are few examples

Kingdom: Fungi• Heterotrophic

eukaryotic organisms.

• Saprophytes.

• Cell wall made of chitin.

• Some of them live in close relationship with certain algae and plants forming Lichens andMycorrhizae.

• Some of them have the ability of being multicellular.

• Yeast, Mushroom and Rhizopus

Kingdom: Plantae

• They are multicellular eukaryotic organisms.

• This kingdom includes all the plant species.

• They are autotrophic and prepare their own food.

• They are further classified into five major divisons

Divison: Thallophyta• Body of the organisms is

not differentiated intoorgans.

• Mainly aquatic found inmarine and fresh water.

• Tissue for conduction ofmaterial and for mechanicalstrength is absent.

• They are covered bymucilage.

• Reproduce by vegetative,asexual and sexualreproduction.

• Algae are example of thisdivison.

Divison: Bryophyta• Plant body is

differentiated into leaf,root and stem likestructures.

• Special conducting tissuesare not present.

• These are known asamphibians of plantkingdoms.

• Reproduce by vegetative,asexual and sexualreproduction.

• Funaria, Anthoceros andMarchantia are fewexamples.

Divison: Pteridophyta• Plant body is differentiated

into leaf, stem and roots.

• They also have conductivetissues.

• All the above discussedplant types doesn’t bearseeds instead they bearspores. They are also knownas cryptograms.

• They require water for thepurpose of reproduction.

• Fern, Adiantum andSelaginella.are fewexamples

Divison: Gymnosperms• These plants bear naked

seeds mean seeds are notenclosed in fruits.

• These are perennial,evergreen trees havingwoody trunk.

• They bear cones in whichseeds are placed.

• Sequoia sempervirens is thelargest tree found on earth(125 Meters) is an example.Other examples are Pinus,Cycas.

Divison: Angiosperms• Bear seeds covered by

special organs known asfruits.

• They bear flowers as theirreproductive organs.

• Embryo in seed has specialstructure called cotyledonswhich act as seed leaves atthe time of germination.

• They are divided into twogroups: Monocots andDicots.

• Wheat, Rice, Rose andTomato are examples ofthis divison.

Kingdom: Animalia• Main characteristics of this kingdom are as follows:

• These are eukaryotic organisms of heterotrophic nature.

• These are multicellular organisms.

• Their cells do not bear cell walls and chloroplasts.

• They are further subdivided into following categories:

Phyllum: Porifera• These animals bear smallholes on their bodysurface.

• They are aquatic andsedentary means nonmotile.

• They have cellular level ofbody design.

• They bear hard externalskeleton and have a canalsystem for thedistribution of food andgases.

• Spongilla and Sycon arethe examples.

Phylum: Coelentrata• They are aquatic animals

and have tissue level ofbody design.

• They have a body cavitycalled coelom so named ascoelentrata.

• They may be solitary orcolonial.

• They have special stingingcells called cnidoblasts soalso known as Cnidaria.

• Hydra, Obelia and Physaliaare few examples.

Phylum: Platyhelminthes• Show bilateral symmetry

and are triploblastic mean have three germ layers.

• They are dorsoventrallyflattened so also called flatworms.

• They are either free living or parasitic.

• They have tissue level of body design.

• They do not have any body cavity

• Planarian and Liver flukes are examples

Phylum: Nematoda• These animals show

bilateral symmetry and aretriploblastic mean havethree germ layers.

• They are cylindrical inshape.

• They have a pseudocoelom.

• They have tissue level ofbody design.

• They are mainly parasitic innutrition.

• Ascaris and Wuchuraria areexamples.

Phylum: Annelida• Show bilateral symmetry

and are triploblastic.

• They are cylindrical inshape and have a true bodycavity.

• Organ system level of bodydesign is found.

• Body is divided into smallsegments called annuli sophylum is also known asAnnelida.

• They found in both land andwater.

• Earthworm and Leech areexamples.

Phylum: Arthropoda• These animals show

bilateral symmetry and aretriploblastic mean havethree germ layers.

• They have a true bodycavity which is blood filled.

• Organ system level of bodydesign is found.

• Open circulatory system isfound in these animals.

• Largest group of animals.

• They have jointed legs.

• Cockroach, Housefly,Butterfly are examples

Phylum:Mollusca• Body cavity is highly

reduced

• These animals show bilateral symmetry and are triploblastic mean have three germ layers.

• They also have open circulatory system.

• They have kidney like structure for excretion.

• A highly muscular foot is used for movement.

• Pila and Chiton are examples

Phylum: Echinodermata• They are spiny skinorganisms.

• They are free livinganimals found only inmarine water.

• They are triploblasticand have true bodycavity.

• They have a tubesystem for the purposeof movement.

• They show high powerof regeneration.

• Starfish and Sea urchinare examples

Phylum: Protochordata• These animals show

bilateral symmetry andare triploblastic meanhave three germ layers.

• They are cylindrical inshape and have a truebody cavity.

• They also have anotochord at any stageof life which providesurface for theattachment of musclesand to provide support.

• Amphioxus,Balanoglossus.

Phylum: Vertebrata• They have notochord

at any stage of life.

• They have a dorsalnerve cord.

• They are triploblastic.

• They have paired gillpouches.

• They have true bodycavity.

• They includes classes:Pisces, Amphibia,Reptilia, Aves andMammalia

Class: Pisces• They are aquatic found in

fresh and marine water.

• Skin is covered by scalesor plates and have gillsfor respiration.

• Body is streamlined andhas a tail.

• They have twochambered heart and arecold blooded.

• Skeleton is made up ofeither cartilage or ofbone.

• Scoliodon and Labeorohita.

Class: Amphibia• They are animals with

uncovered skin whichhelp in gas exchange.

• They have threechambers in heart andare cold blooded.

• They are found in bothwater and on land.

• They lay eggs withoutany hard shell.

• Frog and Salamanders.

Class: Reptilia• They are terrestrial as

well as aquatic.

• Skin is covered byscales.

• They are cold bloodedanimals mostly havingthree chambers in heartexcept crocodile.

• Their eggs are coveredby a hard shell.

• They breathe throughlungs.

• Snakes tortoise.

Class : Aves• They have four chambers in

heart and are warm blooded.

• They breathe through lungs.

• They lay eggs covered by hard shells.

• Their body is covered by feathers and are very good fliers.

• They do not have teeth and bear beak and claws.

• All the birds are examples.

Class : Mammalia• They have four chambers

in heart and are warmblooded.

• They breathe throughlungs.

• They have mammary glandsfor the production of milk.

• They have hairs and nailsas well as sweat and oilglands.

• They give birth to youngones except Platypus andEchidna.

• All the milk producinganimals including humans

Need for Nomenclature:• To solve the problem of many names for any

organism in different areas. Such as LadyFinger (Abelmoschus esculentus) is known byBhindi, Gumbo in different countries.

• To solved out the confusion occurred by thecommon names of some organisms. Such asSilver fish, Cuttle fish are example ofarthropods and mollusks respectively, but thename produce confusion that they belongs toclass Pisce.

How to write Scientific Names

• Carlous Linnaeus introduced the system of providingunique names to each organism.

• Few rules are proposed for naming that are following:

1. Name should be given in Latin language.

2. Name of Genus begins with capital letter.

3. Name of the species begins with small letter.

4. The scientific name should be written in italics whenprinted and should be underlined separately whenhand written.

• Such as the name for Humans is “Homo sapiens”,

for Lion is “Panthera leo”.

That’s for today guys!!!See you later with a new topic!!!

Have a good day