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Tamil Nadu Board Class 8 Science Chapter 16 Microorganisms

if you are looking for Tamil Nadu Board Class 8 Science Chapter 16 Microorganisms then you are at the right place. Here we are providing solutions as well as additional QA / Important Notes.

 

Choose the best answer.

 

Microorganisms are measured in

a) cm b) mm c) micron d) meter.

 

2.____shows both living and nonliving characteristics.

a) Protozoa b) Virus c) Bacteria d) Fungi

 

3.____ is a prokaryotic microorganisms.

a) Virus b) Algae c) Fungi d) Bacteria

 

Based on shape, the bacteria are classified into____types.

a) two b) three c) four d) five

 

Common cold in human is caused by ______

a) plasmodium

b) influenza

c) vibrio cholera

d) aphthovirus

 

Fill in the blanks.

 

______is prepared from a mould called penicillium.[Penicillin ]

______are the infectious protein particles.[Prions ]

The infecting virus particle found outside the host cell is_________[virion]

Microorganism can be seen with the help of a ______[microscope]

Bacteria, which has a flagellum at one end is classified as _______[monotrichous]

 

III. State true or false. If false, correct the statement.

  1. Disease causing microorganisms are called pathogens. [True]
  2. Female anopheles mosquito is a carrier of dengue virus.[False – The female Aedes mosquito is a carrier of the dengue virus.]
  3. Chicken pox is a communicable disease.[True]
  4. Citrus canker is transmitted by insects.[True]
  5. Yeast is used in the large scale production of alcohol.[True]

 

Match the following.

  • Nitrogen fixing bacteria –  Vaccine
  • Tuberculosis   –  Prion
  • Kuru  –  Lactobacillus acidophilus
  • Probiotics – Bacteria
  • Edward Jenner – Rhizobium

 

Solution:-

  • Nitrogen fixing bacteria – Rhizobium
  • Tuberculosis – Vaccine
  • Kuru – Prion
  • Probiotics – Lactobacillus acidophilus
  • Edward Jenner – Vaccine

 

Answer the following questions.

Mark the correct one as:

  • If both assertion and reason are true and reason is the correct explanation of assertion.
  • If both assertion and reason are true and reason is not the correct explanation of assertion.
  • If assertion is true but reason is false.
  • If both assertion and reason are false.

 

Assertion: Malaria is caused by Protozoa. Reason: The disease is transmitted by mosquito.

Ans- If both assertion and reason are true and reason is the correct explanation of assertion.

 

Assertion: Algae are heterotrophic. Reason: They do not have chlorophyll.

Ans – If both assertion and reason are false.

 

Answer very briefly.

 

Write the name of any nitrogen fixing bacteria.

Rhizobium

 

Name the bacteria used in the production of vinegar.

Acetobacter

 

Write the names of any three protozoans.

Amoeba, Paramecium, Plasmodium

 

Who discovered penicillin?

Sir Alexander Fleming

 

Which diseases can be prevented by vaccination?

Measles, Mumps, Rubella, Smallpox, Polio, Influenza, Hepatitis B, Diphtheria, Tetanus, Whooping cough (Pertussis)

 

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