Diversity in living organisms

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Biology Project

• Diversity In Living Organisms

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Content

• Introduction
• Classification
• Basis Of Classification
• System Of Classification
• Hierarchy Of Classification
• Five Kingdoms
• Plantae
• Animalia
• Vertebrata

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Introduction

• Every organism whether plant or animal is unique
  in itself. There is a wide diversity in the flora
  (plants) and fauna (animals) in the world. The
  diversity we see today is the result of 3.5
  billion years of organic evolution. During the
  course of this evolution several species vanished
  from the surface of the Earth and became extinct.
  It is estimated that more than fifty times the
  existing species have become extinct. With such a
  vast number of organisms - both living and
  extinct, it becomes impossible to study every one
  of them at individual level. This task of
  studying the diversity of living organisms can be
  made easier and more effective if the various
  organisms are arranged in an orderly manner.

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Classification

• Classification of organisms may be defined as a
  system of arrangement of organisms into different
  groups and sub-groups on the basis of their
  similarities, differences and relationship.
• Classification of organisms is also known as
  taxonomy. It has the following advantages.
• 1. Classification makes the study of a wide
  variety of organisms convenient and easy.
• 2. It is not possible for man to know about all
  the organisms but the study of a few
  representatives from each taxonomic group gives a
  general idea of all life forms at a glance.
• 3. Classification also reveals the
  interrelationship among different gr4oups of
  organisms.
• 4. Correct identification of an organism and its
  placement in a definite taxonomic group is the
  basic requirement of various branches of
  biological sciences. Thus, classification of
  organisms provides a base for the development of
  other biological sciences.

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Basis Of Classification

• Classification can be done on the following
  basis.
• 1. Cells are prokaryotic or eukaryotic. Organisms
  may be grouped into two broad categories on the
  basis whether they possess prokaryotic cells or
  eukaryotic cells. In case of prokaryotic cells
  the nuclei and other organelles are not clearly
  demarcated. The eukaryotic cells, on the other
  hand, have membrane-bound organelles, including a
  nucleus.
• 2. Cells occur singly or in clusters. Many
  organisms are unicellular, i.e. made up of only
  one cell, e.g. Amoeba. Others are multicellular,
  i.e., cells group together to form single
  organism (e.g., insect). In case of multicellular
  organisms the different groups of cells carry out
  specialized functions
• 3. Organism is photosynthetic or takes food from
  outside. Green plants perform photosynthesis an
  synthesis their own food. Animals cannot perform
  photosynthesis. They get food from outside.
• 4. Organization of different body parts. Grouping
  of organisms may be done on the basis of body
  organization. For example, plants possess stem,
  root and leaves. Similarly, the animals possess
  specialized organs to perform different function.
  The characteristic based on body design used for
  classification of plants is quite different when
  used for classifying animals.

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Systems of classification

• Whittaker characteristics 1. Cell Structure 2.
  Body Structure 3. Mode Of Nutrition .
• He proposed five kingdoms, namely Monera
  ,Protista, Fungi, Plantae and Animalia .
• Eichler characteristics 1. Morphology 2.
  Presence or Absence of Vascular tissue 3.
  Presence or Absence of Fruits , Seeds and Leaves
  4. Seeds are inside the fruit or outside the
  fruit 5. Seeds are dicots or monocots .

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Hierarchy Of Classification

• In classification, the organisms that closely
  resemble one another are placed in a group. These
  groups are further placed in large groups on the
  basis of close similarities. The larger groups
  are again placed in still larger grouping levels
  or ranks in classification are known as
  categories. Each category has its specific name.

There are seven major categories 1. Species 2.
Genus 3. Family 4. Order 5. Class 6. Phylum
(for animals)/division (for plants) 7. Kingdom
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The Five Kingdom Classification Chart
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Kingdom Monera

• They dont well defined body.
• Unicellular structure
• Mode of nutrition heterotropes/autotropes
• They are tiny and single celled.

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Kingdom Protista

• Unicellular And Eukaryotic organisms
• May be autotropes or heterotropes
• Hair-like structure called cilia or whip-like
  called flagella
• They are single-celled and primary aquatic

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Kingdom Fungi

• They are heterotropic eukaryotic organisms
• May be unicellular or multicellular
• Tough complex sugar called chitin.
• The network of Hyphae called mycilium.

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Kingdom Plantae

• They are autotropes,multicellular,eukaryotes with
  cell walls.
• Presence of chlorophyll for photosynthesis.
• They are irregular due to presence of branches.
• They reproduce by both sexual and asexual.

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Kingdom Animalia

• They are multicellular,heterotropes,eukaryotes
  without cell walls.
• Growth of animals is limited
• They have definite shape,size and symmetry.
• Absebce of chlorophyll
• Move with cilia or flagella

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Plantae
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Thallophyta

• Plant Body is not differentiated into root,steem
  or leaves.
• They are autotropes and eukaryotic plants.
• Presence of chlorophyll for photosynthesis.
• The are predominantly aquatic.

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Bryophyta

• These are called the amphibians of the plant
  kingdom.
• The plant body is commonly differentiated to form
  stem and leaf-like structures.
• However, there is no specialised tissue for the
  conduction of water and other substances from one
  part of the plant body to another. 

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Pteridophyta

• 1. The plant body is differentiated into roots,
  stem, and leaves.
• 2. The dominant phase or plant body is a
  sporophyte.
• 3. They are seedless vascular plants and hence
  called vascular cryptogams.
• 4. The gymetophyte is small or inconspious.
• 5. The sex organs are multicellular.

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Gymnosperms

• They have well developed vascular tissues but
  lack vessels
• They bear naked seeds.
• They are unbranched stems.
• They are perennial, evergreen and have conifal
  leaves.

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Angiosperms

• The plants of this group bears covered seeds
  (angio means covered and sperma means seed).
  They are also called flowering plants. The plant
  embryo in the seed have cotyledons.
• Angiosperms are divided into two groups on the
  basis of the number of cotyledons. Plants with
  seeds having single cotyledon are called
  monocots. Eg - rice, wheat, maize etc. green
  gram, peas, tamarind etc. Plants with seeds
  having two cotyledons are called dicots. Eg -
  green gram, peas, tamarind etc.

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Animalia
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Porifera

• Poriferans are commonly called sponges.These
  are multicellular organisms.
• Body is cylindrical, asymmetrical or has radial
  symmetry.
• Reproduction may be asexual or sexual.
• Asexual reproduction takes place by external or
  internal budding.
• Sexual reproduction involves internal
  fertilization.

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Coelenterata

• All are aquatic, mostly marine but a few are
  fresh water forms.
• They may be solitary or colonial. They may be
  sedentary or free-swimming. Head and segmentation
  is absent.
• Mouth is present. Anus is absent.
• Mouth leads into a central cavity called
  'Coelenteron. Hence the name Coelenterate'.
• Respiratory, circulatory and excretory systems
  are absent.
• Nutrition is intercellular and intracellular.
• Asexual reproduction is by budding.Sexual
  reproduction takes place by the development of
  gonad and sex cells. Planula larva is seen.

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Plantyhelminthes

• They are soft bodied, unsegmented worms.
• They show bilateral symmetry and dorsiventrally
  flat worms
• Exo or Endo skeleton is completely absent.
• A true body cavity or coelome is absent, and the
  space between the body organs is filled with
  loose parenchyma.
• The alimentary canal is either absent or highly
  branched. Anus is absent.
• Circulatory and respiratory systems are absent.
• Fertilization is internal and development may be
  direct or indirect.
• May be free living (Turbellaria), ectoparasitic
  or endoparasitic. A few may be commensals.

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Nematoda

• They have cylindrical body.The body is
  bilaterally symmetrical and triploblastic.
• They do not have true body cavity.
• They have tissues but no real organs.They are
  parasitic.

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Annelida

• Their body is bilaterally symmetrical and
  triploblastic.
• They have true body cavity.Their body is
  segmented.
• There is differentiation of organs.
• They are found in water and on land.

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Arthropoda

• They have bilaterally symmetrical body.
• They have an open circulatory system.
• The body cavity is filled with blood.
• They have jointed legs . The body is segmented.

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Mollusca

• They have bilateral symmetry . The coelomic
  cavity is reduced . There is little segmentation.
• They have open circulatory system and kidney like
  organs
• for excretion . They have feet for moving around.

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Echinodermata

• They are spiny skinned organisms.They are free
  living marine animals.They are triploblastic.
• The have water filled tube feet which help in
  movement.
• They have hard skeleton made of calcium
  carbonate.

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Protochordata

• They have bilateral symmetry and are
  tiploblastic.
• The have coelomic cavity.
• The have a notocord which is a long rod-like
  structure along its back to which muscles are
  attached and help in movement.

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Vertabrata

• They have vertebral column and internal skeleton.
• They have bilateral symmetry and are
  triploblastic.
• They have coelomic cavity.
• Their body is differentiated into tissues and
  organs.
• Their body consists of four regions head,
  neck, trunk
• and tail.
• They have two pairs of fins or limbs.
• The respiration in aquatic forms is by gills and
  in land
• forms respiration is by lungs
• The sexes are separate.
• Vertebrates are grouped into five classes.
  
• They are -
• Pisces, Amphibia, Reptilia, Aves and
  Mamalia

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Pisces

• They are aquatic vertebrates that live in water
• They have paired appendages in the form of fins.
  Unpaired fins are also present. They respire with
  the help of gills.
• Fishes have a two chambered heart and there is a
  single circulation of blood . Respiration is
  typically by pharyngeal gills
• Skin is generally covered by protective dermal
  scales skin glandular.
• Nasal cavity is not connected to the buccal
  cavity.
• Internal skeleton is either cartilaginous or
  bony.
• Sexes are separate fertilization is external or
  internal.
• Gonads and true gonoducts are present. Amnion is
  absent

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Amphibia

• They are found in land and water.
• They do not have scales but have mucous glands on
  their skin. They lay eggs in water.
• They are cold blooded and the heart is three
  chambered.
• Respiration is through gills or lungs.

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Reptilia

• Reptiles are considered as tetra pods with two
  sets of paired limbs.
• All reptiles have spinal columns and a strong
  skeletal system with a rib cage. They have a
  well-developed brain and a central nervous
  system.
• All reptiles have three-chambered hearts, except
  crocodiles, which have four-chambered hearts (2
  atria, 2 ventricles), like mammals and birds.
• Reptiles have a digestive system which has a
  muscular opening at the base of the tail . Twelve
  pairs of cranial nerve . Respiration by lungs
  only.
• Lateral sense organs are absent.
• Reptile's characteristics include internal
  fertilization, as sperm gets deposited into the
  reproductive tract of the female directly . The
  cloaca is present

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Aves

• The members of class aves are commonly known as
  birds.
• They are worm-blooded with an exoskeleton of
  feathers.
• Body usually spindle shaped, with four divisions
  head, neck, trunk, and tail neck
  disproportionately long for balancing and food
  gathering. No sweat glands
• Oil or preen gland at base of tail.
• No teeth ribs with strengthening, uncinate
  processes.
• Single bone in middle ear. Prental care is well
  developed.
• Fused bones in pelvis, feet, hands, and head
• Sexes separate testes paired, with the vas
  deferens opening into the cloaca.
• Females have left ovary and oviduct only.

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Mammalia

• Corpus callosum in eutherians provides additional
  communication
• Smell acute except whales and higher apes . Eye
  typical of amniotes.
• Tapetum lucidum well developed in nocturnal
  mammals.
• Touch- most have vibrissae that are controlled by
  facial muscles.
• Lateral movement of jaw during mastication.
• Viviparous except monotremes which are egg lying.
• Parental care well developed . Highly developed
  neopallium.
• Teeth are imbedded in the jaw bone and come in a
  variety of forms.
• Well developed brain. Warm blooded.
• Endothermic. The majority of the heat energy is
  used to maintain their high body temperature .
  Four chambered heart.
• Seven cervical vertebrae (neck bones) are present
  in most mammals

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Nomenclature

• Binomial nomenclature is the formal naming system
  for living things that all scientists use. It
  gives every species a two-part scientific name.
  For example, a ladybug found in the United States
  goes by the fancy name of Harmonia axyridis.
• The first part of a scientific name,
  like Harmonia, is called the genus. A genus is
  typically the name for a small group of closely
  related organisms. The second part of a
  scientific name, axyridis in this example, is
  the specific epithet. It is used to identify a
  particular species as separate from others
  belonging to the same genus. Together, the genus
  plus the specific epithet is the full scientific
  name for an organism.
• The entire two-part name must be written in
  italics (or underlined when handwritten).
• The genus name is always written first.
• The genus name must be capitalized.
• The specific epithet is never capitalized.

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