viva

• The number of bacteria and microbes present in our body is more than the number of all the cells forming our body
• Bacteria


  Non-nucleated unicellular heterotrophic microorganisms with murin cell wall
• Bacterium


  Singular form of bacteria
• Majority of bacteria are autotroph while few are heterotroph (photosynthetic and chemosynthetic)
• Bacterial diseases


  • Cholera
  • Tuberculosis
• Where bacteria are found

  • Mouth
  • Intestine
  • Skin
  • Air we breathe in
• Anton Van Leeuwenhoek, a Dutch scientist, first observed bacteria from stagnant water

  1676
• How bacteria are useful

  • Convert milk into curd
  • Convert sugar cane juice into vinegar
  • As decomposers, break down dead organic matter and recycle them
  • Play important role in digestion of food in our digestive canal
• Capsule


  Gives protection to bacteria
• Flagella


  Helps in locomotion of bacteria
• Parasite


  An organism which lives in (or on) the body of another organism (host) and derives food from it
• Pathogenic parasite


  A parasite which causes disease to its host
• Entamoeba histolytica


  Found in the intestine of man, destroys the intestinal lining and causes Amoebic dysentery or Amoebiasis, also causes abscess of liver
• Cilia of Paramecium


  • Help in fast movement or swimming
• Generally plant organisms are found near the surface of pond water because they need light for the preparation of food. The organisms which have the ability to attach themselves with the base, will prefer to stay at the bottom. Those micro-organisms which can swim will also be found near the surface
• Organs of locomotion


  • Amoeba - Pseudopodia
  • Paramecium - Cilia
  • Euglena - Flagellum
• Important structures in ectoplasm and endoplasm of Paramecium

  • Ectoplasm - Contractile vacuoles, Trichocysts
  • Endoplasm - Food vacuoles, Micro and mega nuclei
• Micronucleus


  Controls the reproductive activity of Paramecium
• Meganucleus


  Controls the metabolic activities of Paramecium
• Methods of reproduction in Paramecium

  • Asexual - Binary fission
  • Sexual - Conjugation
• Organisms with slipper shaped body

  • Paramecium
• Decomposing type of bacteria produced in large number in Petri dish A


  No organisms found in Petri dish B due to effect of cold
• Maximum number of micro-organisms observed in pond water sample
• Volvox


  Means to roll
• Colonies of Volvox


  • In the form of small green balls, of the size of pin-head just visible to naked eye
• Natural habitat of Volvox is the surface layer of freshwater of ponds, pools and ditches
• All the cells of the Volvox colony are similar in shape, size and structure
• Eye-spot


  Distinguishes between light and darkness
• Pyrenoid


  Converts sugar into starch
• Composition of blood


  • Red cells
  • White cells
  • Platelets
  • Plasma
• Red blood cells have nuclei during their formation but lose them before entering circulation
• Red blood cells


  Made principally in the red bone marrow of the short bones such as the sternum, ribs and vertebrae
• The total duration for the formation of red cells is seven days
• Types of white blood cells

  • Granulocytes
  • Lymphocytes
  • Monocytes
• Platelets


  Irregularly shaped objects about 0.003 mm, they play important role in blood clotting in wounds
• Phagocytes


  Form the body's chief defense mechanism against disease causing bacteria, they gather in wounds and destroy bacteria before they can enter the body
• Shape of blood corpuscles


  Related to their function
• Anticoagulant


  Checks blood from clotting
• Lymphocytes


  Part of immune system that protect us from microbes, B lymphocytes produce antibodies and T lymphocytes are involved in graft rejection
• Neutrophils


  Involved in the process of inflammation and phagocytosis