Diversity in Living Organism

DIVERSITY IN LIVING ORGANISM

P. MonishIX-B

KV CRPF

DIVERSITY IN LIVING ORGANISM

Classification

Science of arranging organisms in series of groups and subgroups on the basis of their similarities and dissimilarities.

Aristotle classified organisms on the basis of their habitat means the place where they live, in water, in air and on land.

Basic characteristics of classification

• 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

• Time is the key factor which helps in development of complex organisms from the simple ones.

• Charles Darwin firstly gave the idea of evolution in 1859 in his famous book ‘The Origin of Species’.

• Those organisms which have ancient body design and not changed much are called Primitive organisms.

• Those who acquired certain special characters during the time period are known as advanced or higher organisms.

Biodiversity

• Biodiversity is the term used for the various forms of life found in a given area.

• These life forms depends on each other and on the environment and results in a stable community.

• Human also is the part of this biodiversity. • It is estimated that there is about 10,000,000 species on

this planet, we know only about 20,00,000 species.

Hierarchy of classification

• Ernst Haeckel, Robert Whittaker, Carl Woese have tried to classify all living organisms into broad categories.

• R. Whittaker proposed five kingdom system which is widely used. This kingdom includes Monera, Protista, Fungi, plantae and Animalia.

• Carl Woese divided Monera into Archaebacteria and Eubacteria.

Further Classification• Living organisms have been broadly classified into five main kingdoms. • They are :-

i) Monera ii) Protista iii) Fungi iv) Plante v) Animalia

• Each kingdom has been further classified into smaller sub - groups at various levels as :- Kingdom Phylum (for plants) / Division (for animals) Class Order Family Genus Species • By arranging organisms on the basis of hierarchy and characteristics into smaller and smaller groups we arrive at the basic unit of classification called species.

Further classification

Further classification is done by naming the sub groups at Various levels as given: Kingdom→Phyllum\Division→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, cyanobacteria and

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, protozoa 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 and Mycorrhizae.

• Some of them have the ability of being multi-cellular.

• Yeast, Mushroom and Rhizopus

Kingdom: Plantae

• They are multi-cellular eukaryotic organisms.• This kingdom includes all the plant species.• They are autotrophic and prepare their own food.• They are further classified into five major divisions

Division: Thallophyta

• Body of the organisms is not differentiated into organs.

• Mainly aquatic found in marine and fresh water.

• Tissue for conduction of material and for mechanical strength is absent.

• They are covered by mucilage.• Reproduce by vegetative,

asexual and sexual reproduction.• Algae are example of this

division.

Division: Bryophyta

• Plant body is differentiated into leaf, root and stem like structures.

• Special conducting tissues are not present.

• These are known as amphibians of plant kingdoms.

• Reproduce by vegetative, asexual and sexual reproduction.

• Funaria, Anthoceros and Marchantia are few examples.

Division: Pteridophyta

• Plant body is differentiated into leaf, stem and roots.

• They also have conductive tissues.

• All the above discussed plant types doesn’t bear seeds instead they bear spores. They are also known as cryptograms.

• They require water for the purpose of reproduction.

• Fern, Adiantum and Selaginella are few examples

Division: Gymnosperms

• These plants bear naked seeds mean seeds are not enclosed in fruits.

• These are perennial, evergreen trees having woody trunk.

• They bear cones in which seeds are placed.

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

Division: Angiosperms

• Bear seeds covered by special organs known as fruits.

• They bear flowers as their reproductive organs.

• Embryo in seed has special structure called cotyledons which act as seed leaves at the time of germination.

• They are divided into two groups: Monocots and Dicots.

• Wheat, Rice, Rose and Tomato are examples of this division.

Kingdom: Animalia

• Main characteristics of this kingdom are as follows:• These are eukaryotic organisms of heterotrophic nature.• These are multi-cellular organisms.• Their cells do not bear cell walls and chloroplasts.• They are further subdivided into following categories:

Phyllum: Porifera

• These animals bear small holes on their body surface.

• They are aquatic and sedentary means non motile.

• They have cellular level of body design.

• They bear hard external skeleton and have a canal system for the distribution of food and gases.

• Spongilla and Sycon are the examples.

Phylum: Coelentrata

• They are aquatic animals and have tissue level of body design.

• They have a body cavity called coelom so named as coelentrata.

• They may be solitary or colonial.• They have special stinging cells

called cnidoblasts so also known as Cnidaria.

• Hydra, Obelia and Physalia are few examples.

Phylum: Platyhelminthes

• Show bilateral symmetry and are triploblastic mean have three germ layers.

• They are dorsoventrally flattened 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 are triploblastic mean have three germ layers.

• They are cylindrical in shape.• They have a pseudocoelom.• They have tissue level of body

design.• They are mainly parasitic in

nutrition.• Ascaris and Wuchuraria are

examples.

Phylum: Annelida

• Show bilateral symmetry and are triploblastic.

• They are cylindrical in shape and have a true body cavity.

• Organ system level of body design is found.

• Body is divided into small segments called annuli so phylum is also known as Annelida.

• They found in both land and water.

• Earthworm and Leech are examples.

Phylum: Arthropoda


• They have a true body cavity which is blood filled.

• Organ system level of body design is found.

• Open circulatory system is found 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 skin organisms.• They are free living animals

found only in marine water.• They are triploblastic and

have true body cavity.• They have a tube system for

the purpose of movement.• They show high power of

regeneration.• Starfish and Sea urchin are

examples

Phylum: Protochordata


• They are cylindrical in shape and have a true body cavity.

• They also have a notochord at any stage of life which provide surface for the attachment of muscles and to provide support.

• Amphioxus, Balanoglossus.

Phylum: Vertebrata

• They have notochord at any stage of life.

• They have a dorsal nerve cord.

• They are triploblastic.• They have paired gill

pouches.• They have true body

cavity.• They includes classes:

Pisces, Amphibia, Reptilia, Aves and Mammalia

Class: Pisces

• They are aquatic found in fresh and marine water.

• Skin is covered by scales or plates and have gills for respiration.

• Body is streamlined and has a tail.

• They have two chambered heart and are cold blooded.

• Skeleton is made up of either cartilage or of bone.

• Scoliodon and Labeo rohita.

Class: Amphibia

• They are animals with uncovered skin which help in gas exchange.

• They have three chambers in heart and are cold blooded.

• They are found in both water and on land.

• They lay eggs without any hard shell.

• Frog and Salamanders.

Class: Reptilia

• They are terrestrial as well as aquatic.

• Skin is covered by scales.• They are cold blooded

animals mostly having three chambers in heart except crocodile.

• Their eggs are covered by a hard shell.

• They breathe through lungs.

• 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 warm blooded.

• They breathe through lungs.• They have mammary glands for

the production of milk.• They have hairs and nails as

well as sweat and oil glands.• They give birth to young ones

except Platypus and Echidna.• All the milk producing animals

including humans

Thank you