LEVELS OF ORGANIZATION
IN ORDER TO UNDERSTAND THE PHENOMENA OF LIFE,BIOLOGISTS STUDY BIOLOGICAL ORGANIZATION
 AT DIFFERENT LEVELS ,WHICH ARE AS FOLLOWS;

  • SUBATOMIC PARTICLES
  • MOLECULAR LEVEL
  • ORGANELLE AND CELL LEVEL
  • TISSUE LEVEL
  • ORGAN AND ORGAN SYSTEM LEVEL
  • INDIVIDUAL LEVEL
  • POPULATION LEVEL
  • COMMUNITY LEVEL
  • BIOSPHERE LEVEL
 SUBATOMIC PARTICLES
➤ALL THE LIVING ORGANISMS ARE MADE UP OF ELEMENTS. AND EACH ELEMENT CONTAINS A SINGLE
    KIND OF ATOM ATOMS ARE FURTHER COMPOSED OF SUBATOMIC PARTICLES. SUBATOMIC PARTICLES 
   ARE SMALLER IN SIZE THAN AN ATOM.TYPICALLY ATOM IS BROKEN DOWN INTO THREE SUBATOMIC
   PARTICLES NEUTRON,ELECTRON  AND PROTON.THESE ARE MOST STABLE SUBATOMIC PARTICLES.

levels of organization

BIO-ELEMENTS

➤OUT OF THE 92 KINDS O ELEMENTS THAT OCCUR IN NATURE, 16 ARE CALLED BIO-ELEMENTS.THESE
   TAKE PART IN MAKING THE BODY MASS OF AN ORGANISM.BIO-ELEMENTS  ARE  ALSO REQUIRED FOR
   SURVIVAL AND GROWTH OF LIVING ORGANISMS.

OUT OF THESE BIO-ELEMENTS; 

★ONLY SIX (O,C,H,N,Ca & P) MAKE 99%OF THE TOTAL MASS.

★OTHER TEN (K,S,Cl,Na,Fe,Cu,Mg,Mn,Zn, & I) 

MOLECULAR LEVEL

➤IN ORGANISMS, BIOELEMENTS USUALLY  DO NOT OCCUR IN ISOLATED FORM RATHER THEY COMBINE
   THROUGH IONIC OR COVALENT BONDING THE STABLE PARTICLE FORMED BY SUCH BONDING IS
  CALLED AS MOLECULE OR BIOMOLECULE. AN ORGANISM IS FORMED BY  ENORMOUS NUMBER OF
  BIOMOLECULES OF DIFFERENT VARIETY.

levels of organization

CLASSIFICATION

➤ BIOMOLECULES ARE CLASSIFIED IN TWO FORMS;

  • MICROMOLECULES 
  • MACROMOLECULES

MICROMOLECULES

➤THE MOLECULES WHICH ARE REQUIRED IN SMALL QUANTITY IS CALLED BIOMOLECULES.

   EXAMPLES;   

   SUGAR,NUCLEIC ACID ,FATTY ACID,WATER, MINERALS, AMINO ACIDS ETC.

MACROMOLECULES

➤THE MOLECULES WHICH ARE REQUIRED IN LARGE QUANTITY ARE CALLED MACROMOLECULES.

EXAMPLES; CARBOHYDRATES, LIPIDS, STARCH, PROTEINS ETC.

ORGANELLE AND CELL LEVEL

➤BIOMOLECULES ASSEMBLE IN A PARTICULAR WAY  AND FORM ORGANELLES. THESE ARE THE SUB-

    CELLULAR  STRUCTURE  IN THE CELL. EACH ORGANELLE IS SPECIALIZED TO PERFORM  A SPECIFIC

    FUNCTION.

FOR EXAMPLE;

➤MITOCHONDRIA ARE SPECIALIZED FOR CELLULAR RESPIRATION.RIBOSOMES ARE  SPECIALIZED  FOR

    PROTEIN SYNTHESIS.

IN CASE OF PROKARYOTES AND MOST PROTIST;

➤THE ENTIRE ORGANISM CONSIST OF A SINGLE CELL.

IN CASE OF MOST FUNGI, ANIMALS, AND PLANTS;

➤THE ORGANISM CONSIST OF UP TO TRILLION OF CELLS.

levels of organization

TISSUE LEVEL

➤IN MULTICELLULAR ORGANISMS SIMILAR CELLS ( PERFORMING  SIMILAR FUNCTIONS) ARE ORGANIZED

     INTO GROUPS CALLED TISSUE.

OTHER DEFINITION;

➤WE CAN DEFINE A TISSUE AS A GROUP  OF SIMILAR CELLS SPECIALIZED FOR THE PERFORMANCE OF A

   COMMON FUNCTION.

LIFE PROCESSES;

➤EACH CELL IN A TISSUE CARRIES ITS OWN LIFE PROCESSES (LIKE CELLULAR RESPIRATION,PROTEIN

   SYNTHESES), BUT IT ALSO CARRIES ON SOME SPECIAL PROCESSES RELATED TO THE FUNCTION OF 

   TISSUE.

EXAMPLE; 

➤THERE ARE DIFFERENT TYPES OF PLANT TISSUES; EPIDERMAL TISSUES, GROUND TISSUES,ETC.

  ANIMAL TISSUES ARE OF DIFFERENT TYPES; NERVOUS TISSUE, MUSCULAR TISSUE.

levels of organization


ORGAN AND ORGAN SYSTEM LEVEL

ORGAN

➤IN HIGHER MULTICELLULAR ORGANISMS MORE THAN ONE TYPE OF TISSUE HAVING RELATED

   FUNCTIONS ORGANIZED TOGETHER AND MAKE  A UNIT, CALLED ORGAN.

DIFFERENT TISSUES OF AN ORGAN

➤DIFFERENT TISSUES OF AN ORGAN PERFORM THEIR SPECIFIC FUNCTIONS AND THESE FUNCTIONS

   BECOME THE FUNCTION OF THAT ORGAN.

FOR EXAMPLE; 

➤STOMACH IS AN ORGAN SPECIALIZED FOR THE DIGESTION PROTEINS AND FOR STORING FOOD.

TWO MAJOR TYPES OF TISSUES PRESENT IN ITS STRUCTURE;

EPITHELIAL (GLANDULAR) TISSUE SECRETES GASTRIC JUICE FOR THE DIGESTION OF PROTEINS.

➤MUSCULAR TISSUE PERFORM CONTRACTIONS OF STOMACH WALL FOR GRINDING OF FOOD AND

  MOVING FOOD TO POSTERIOR END.SO TWO TISSUES PERFORM THEIR SPECIFIC FUNCTIONS, WHICH

  COLLECTIVELY  BECOME THE  FUNCTION OF  STOMACH.

ORGAN SYSTEM LEVEL 

➤THE NEXT LEVEL OF ORGANIZATION IN MULTICELLULAR ORGANISMS IS THE ORGAN SYSTEM LEVEL.

   DIFFERENT ORGANS PERFORMING RELATED FUNCTIONS ARE ORGANIZED  TOGETHER IN THE FORM OF

   AN ORGAN SYSTEM.

FUNCTION

➤IN AN ORGAN SYSTEM, EACH ORGAN CARRIES OUT ITS SPECIFIC FUNCTION  AND THE FUNCTIONS OF

   ALL ORGANS APPEAR; AS THE FUNCTION OF THE ORGAN SYSTEM. 

FOR EXAMPLE; 

➤DIGESTIVE SYSTEM IS AN ORGAN SYSTEM  THAT CARRIES OUT THE PROCESS OF DIGESTION. MAJOR

   ORGANS IN ITS FRAMEWORK ARE ORAL CAVITY, STOMACH, SMALL INTESTINE, LARGE INTESTINE, LIVER,

   AND PANCREAS. ALL THESE ORGANS HELP IN THE PROCESS OF DIGESTION.

levels of organization