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[2 Mark Questions]

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12 questions · timed · auto-graded

Question 22 Marks
Mention the symptoms and preventive measures undertaken for foot and mouth disease in animals.
Answer
Animal diseasesymptomsPreventive measures/ Treatment
Foot and mouth diseaseFever, blisters in mouth, weight loss, decreased milk productionFMD vaccine
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Question 32 Marks
What is retting?
Answer
Flax plants are tied in bundles and kept in water. Bacteria loosen the supporting fibres of the stem by acting on the stem tissues. This process is known as retting.
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Question 42 Marks
What is pseudopodia?
Answer
In amoeba pseudopodia are the extended part of cell membrane. It helps to catch its prey (algae).
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Question 52 Marks
How are protozoans classified?
Answer
  1. Ciliates – presence of cilia for locomotion (e.g. Paramecium)
  2. Flagellates – presence of flagella for locomotion (e.g. Euglena)
  3. Pseudopods – presence of pseudopodia for locomotion (e.g. Amoeba)
  4. Sporozoans – parasites (e.g. Plasmodium)
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Question 72 Marks
Mention two non living characteristics of viruses.
Answer
  1. They are inactive when present freely in the environment.
  2. They can be crystallized and stored for a very long time, like other non – living things.
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Question 82 Marks
Mention two living characteristics of viruses.
Answer
  1. They respond to heat, chemicals and radiations.
  2. They reproduce inside the host cells and produce copies of themselves.
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Question 92 Marks
How microorganisms are useful in the field of medicine?
Answer
Role of microbes in medicine:
We obtain antibiotics and vaccines from microbes.
  1. Antibiotics: It is a substance produced by living organisms which is toxic to other organisms. The antibiotic penicillin got from the fungus Penicillium chrysogenum is used to treat diseases like tetanus, diphtheria. Streptomycin got from streptomyces bacteria is used to cure bacterial infections like the plague.
  2. Vaccines: They are prepared from dead or weakened microbes. When a vaccine is injected into the body of a patient, it produces antibodies to fight the germs. These antibodies protect the body from infections in the future. Example: MMR vaccine for measles.
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Question 102 Marks
What are antibiotics?
Answer
Antibiotic is a substance produced by living organisms which is toxic for other organisms.
Example: Penicillin.
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Question 112 Marks
Write the four types of bacteria, based on their shape.
Answer
Bacteria are described according to the shape of their cells. They are:
  1. Bacilli – Rod-shaped bacteria.
  2. Spirilla – Spiral-shaped bacteria.
  3. Cocci – Spherical or ball-shaped bacteria.
  4. Vibrio – comma-shaped bacteria.
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[2 Mark Questions] - Science STD 8 Questions - Vidyadip