KERALA PSC / BIOLOGY / MICRO ORGANISMS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

 

KERALA PSC / BIOLOGY / MICRO ORGANISMS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / BIOLOGY / MICRO ORGANISMS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

·      The study of microorganisms is called microbiology

·      According to shape, bacteria are classified into five. They are:

Ø Cocci – Sperical or Oval Cell

Ø Bacilli – Rod shaped cell

Ø Vibrios – Comma shaped, curved rodes

Ø Spirilla – Rigid spiral forms

Ø Spirochetes – Flexons spiral forms

·      Anton Von Leewenhock discovered microorganisms in 1675, using a microscope of his own design

·      Microorganisms are very diverse; they include bacteria, fungi, archaea, and protists; microscopic plants (green algae); and animals such as plankton and the planarian.

·      Microorganisms live in all parts of the biosphere where there is liquid water, including soil, hot springs, on the ocean floor, high in the atmosphere and deep inside rocks within the Earth’s crust.

·      Bacteria were first observed by Anton Von Leeuwenhoek in 1676.

·      The name bacterium was introduced by Christian Gottfried Ehrenberg in 1838.

·      Bacteria are microscopic unicellular prokaryotic organism and lack of membrane bound nucleus and organelles.

·      Bacteria are eventually placed in a Kingdom Monera.

·      Reproduction in bacteria is largely asexual by binary fission

·      Respiration of bacteria are aerobic and anaerobic

·      Bacteria show a wide diversity of shapes and sizes, called morphologies

·      Bacteriophages are viruses eating (destroying) bacteria and were invented by d’Herelle

·      Bacteriology is the study of bacteria

·      ‘Virus’ the term is coined by M.W Beigerinck, a Dutch microbiologist.

·      A virus is a small infectious agent that can replicate only inside the living cells of organisms

·      All viruses are nucleoprotein particles and contain either DNA or RNA. The genetic material inside the viruses is protected by a protein coat called ‘capsid’

·      Viruses lack the cellular organization of the living organism, but make use of the cellular machinery of the host cell to multiply themselves.

·      A complete viral particle capable of infection is called a ‘virion’.

·      ‘Viroids’ are newly found group of pathogenic agents, much smaller than the viruses.

·      The study of viruses is known as virology, a sub-specialty of microbiology

·      L.S.D (Lysergic acid Diethylamide) is obtained from a fungi, called Ergot.

·      Smallest Cell – Pleuro Pneumonia Like Organism (PPLO). It is a mycoplasma.

·      HIV is an RNA virus.

·      Smallest living thing – Virus

·      Pasteurization of milk: It is the process of heating milk in a properly designed and operated equipment upto 72ºC for atleast 15 second then followed by immediate cooling to 4ºC and storing at low temperature.

KERALA PSC / BIOLOGY / MICRO ORGANISMS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY