Biology BIOLOGICAL CLASSIFICATION

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BIOLOGICAL CLASSIFICATION

Kingdom-Monera (MYCOPLASMA)

# In 1898, two French scientists E. Nocard and R. Roux while studying pleural fluids of cattle suffering from pleuropneumonia disease, discovered the organisms which are known as mycoplasma and were designated as PPLO (i.e. Pleuropneumonia like organism).
# Nowak (1929) put these organisms under the genus Mycoplasma.
#The Japaneese Doi et.al. (1967)first discovered that the "Aster yellow" disease of plants are caused by Mycoplasma. Doi et.ai. named these pleomorphic organisms as mycoplasma like organisms (MLO). According to Doi, phloem cells (Sieve tube & phloem parenchyma) of plants are much affected by this disease.

# In 1898, two French scientists E. Nocard and R. Roux while studying pleural fluids of cattle suffering from pleuropneumonia disease, discovered the organisms which are known as mycoplasma and were designated as PPLO (i.e. Pleuropneumonia like organism).
# Nowak (1929) put these organisms under the genus Mycoplasma.
#The Japaneese Doi et.al. (1967)first discovered that the "Aster yellow" disease of plants are caused by Mycoplasma. Doi et.ai. named these pleomorphic organisms as mycoplasma like organisms (MLO). According to Doi, phloem cells (Sieve tube & phloem parenchyma) of plants are much affected by this disease.

MAIN POINTS

1. Mycoplasmas unicellular, smallest prokaryotic organisms. The diameter of cell varies from 0.1 micro-mt to 0.3 micro-mt.
2. Cell membrane is tri-layered and made up of lipoprotein. Both DNA (ds DNA circular mainly) and RNA (ssRNA) are present.
3. Mycoplasmas may be the simplest form of life capable of independent growth, reproduction and metabolism.
4. They are cell wall less hence they exhibit pleomorphism and thus called as Joker of plant kingdom.
5. Osmotropic mode of nutrition(absorption of nutrients by osmosis) is found in Mycoplasma.
6. They are resistant to antibiotics as penicillin that act on cell wall.
7. They are sensitive to tetracycline & chloramphenicol that act on metabolic activities.
8. Most of the species of Mycoplasma are facultative anaerobs.
9. Species of Mycoplasma are saprophyte or facultative parasite.

Reproduction :
1. Binary Fission : Most common method of reproduction in mycoplasma.
2. By primary structures or "Elementary bodies"

Plant Disease :
1. Little leaf disease of Brinjal.
2. Bunchy top of papaya.
3. Witches broom of Ground nut (Legume)/ Potato
4. Aster yellow disease of sunflower.
Note : In plants, mycoplasmal disease usually transmitted by leaf hopper.

Animal Disease :
(i) M. hominis causes male Sterility/Genitals inflammation in human.
(ii) Mycoplasma mycoides causes bovine pleuropneumnoia.
(iii) Mycoplasma pneummiae causes primary atypical pneumnoia.

1. Mycoplasmas unicellular, smallest prokaryotic organisms. The diameter of cell varies from 0.1 micro-mt to 0.3 micro-mt.
2. Cell membrane is tri-layered and made up of lipoprotein. Both DNA (ds DNA circular mainly) and RNA (ssRNA) are present.
3. Mycoplasmas may be the simplest form of life capable of independent growth, reproduction and metabolism.
4. They are cell wall less hence they exhibit pleomorphism and thus called as Joker of plant kingdom.
5. Osmotropic mode of nutrition(absorption of nutrients by osmosis) is found in Mycoplasma.
6. They are resistant to antibiotics as penicillin that act on cell wall.
7. They are sensitive to tetracycline & chloramphenicol that act on metabolic activities.
8. Most of the species of Mycoplasma are facultative anaerobs.
9. Species of Mycoplasma are saprophyte or facultative parasite.

Reproduction :
1. Binary Fission : Most common method of reproduction in mycoplasma.
2. By primary structures or "Elementary bodies"

Plant Disease :
1. Little leaf disease of Brinjal.
2. Bunchy top of papaya.
3. Witches broom of Ground nut (Legume)/ Potato
4. Aster yellow disease of sunflower.
Note : In plants, mycoplasmal disease usually transmitted by leaf hopper.

Animal Disease :
(i) M. hominis causes male Sterility/Genitals inflammation in human.
(ii) Mycoplasma mycoides causes bovine pleuropneumnoia.
(iii) Mycoplasma pneummiae causes primary atypical pneumnoia.

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