WBBSE Solutions For Class 8 School Science Chapter 7 The Microbial World Very Short Answer Type Questions

Chapter 7 The Microbial World VSAQs

 

Question 1. What are microbes?
Answer:

Microbes:

Microscopic living organisms other than plants and animals.

Question 2. What is the whitish layer, formed on the surface of bread during the rainy season?
Answer:

It is a layer of fungus.

Question 3. What are the most primitive and ancient organisms found on earth?
Answer:

Microbes are the most primitive and ancient organisms.

Question 4. Name one anaerobic microbe.
Answer:

Yeast (or tetanus-causing pathogen) is an anaerobic microbe.

Question 5. What is the term used to denote the organisms living on dead and decaying organic matter?
Answer:

They are called saprotrophs.

Question 6. Which microbes can produce their own food?
Answer:

Algae can produce their own food.

Question 7. What are thermophilic bacteria?
Answer:

Thermophilic Bacteria:

They can grow and survive even at about 100X.

Question 8. What types of bacteria are found in hot springs?
Answer:

Types of bacteria are found in hot springs:

Thermophilic bacteria are found in hot springs.

Question 9. What is staining?
Answer:

Staining:

It is the process of coloring specimens for identification under a microscope.

Question 10. Which cell organelle is present in bacteria?
Answer:

Ribosomes are present in bacteria.

Read And Learn More WBBSE Solutions For Class 8 School Science Very Short Answer Type Questions

Question 11. State the characteristics of bacterial DNA.
Answer:

It is circular DNA, not enclosed within the nucleus.

Question 12. Name a locomotory structure of protozoa, other than pseudopodia.
Answer:

The locomotory structures may be cilia or flagella.

Question 13. What are the units of fungal mycelium?
Answer:

Units of fungal mycelium:

A large number of hyphae form mycelium

Question 14. Give an example of a unicellular roundish fungus.
Answer:

Yeast is a unicellular, roundish fungus.

Question 15. Why fungi can not synthesize their own food?
Answer:

Because they do not have chloroplasts in their cell.

Question 16. Name colonial algae.
Answer:

Colonial algae:

Volvox is a colonial alga.

Question 17. Why algae can synthesize their own food (autotrophic)?
Answer:

Because they have chloroplasts in their cytoplasm.

Question 18. Which microbes cause smallpox?
Answer:

Smallpox is caused by a virus.

Question 19. Which microorganisms do not have a nucleus and cytoplasm?
Answer:

Viruses do not have a nucleus and cytoplasm.

Question 20. What type of nucleic acid is found in viruses?
Answer:

The nucleic acid is either DNA or RNA.

Question 21. Which microbes show the characteristic of living only within the body of a host?
Answer:

Viruses behave like living only within the body of a host.

Question 22. Which type of microbes causes amoebiasis?
Answer:

Some protozoal microbes are responsible.

Question 23. How tuberculosis can spread from one person to other?
Answer:

It can spread through cough and sneezing.

Question 24. Which symbiotic bacteria are found in root nodules of leguminous plants?
Answer:

Rhizobium lives in root nodules.

Question 25. Which symbiotic bacteria live in the human intestine?
Answer:

The symbiotic bacteria Escherichia coli live in the human intestine.

Question 26. Which microbial association is found in Lichen?
Answer:

In lichen, an association of algae and fungi is found.

Question 27. What is the term used to denote the mutually beneficial association between two organisms?
Answer:

The term is symbiosis.

Question 28. How the bacteria Azotobacter is helpful?
Answer:

It helps to fix nitrogen in the soil.

Question 29. What is the function of nitrifying bacteria?
Answer:

It converts ammonia into nitrate and nitrite.

Question 30. Which bacteria help in the formation of curd from milk?
Answer:

The bacteria is Lactobacillus.

Question 31. What is the term used for the process of food preservation in air-tight containers?
Answer:

It is known as canning.

Question 32. By which process, milk can be preserved?
Answer:

It is done by Pasteurization.

Question 33. what are antibiotics?
Answer:

Antibiotics:

These are life-saving drugs produced from microbes.

Question 34. Who first discovered antibiotics?
Answer:

Alexander Flemming first discovered antibiotics in the year 1928.

Question 35. What are antigens?
Answer:

Antigens:

Antigens are foreign substances that may enter our body fluid.

Question 36. What are antibodies?
Answer:

Antibodies:

Antibodies are protein substances produced by our body’s defense mechanism to fight against antigens.

Question 37. What is vaccination?
Answer:

Vaccination:

Vaccination is the administration of antigenic material (a vaccine) to stimulate an individual’s immune system to develop immunity against a pathogen.

Question 38. Name two diseases that can be controlled, by vaccination.
Answer:

Typhoid, tetanus, polio, diphtheria, smallpox, tuberculosis, etc (any two are to be .. mentioned).

Question 39. Which gas may be produced from the treatment of wastes?
Answer:

Methane gas may be produced.

Question 40. Name algae that is used in space shuttles.
Answer:

Chlorella is used to clean the enclosed air.

Question 41. Name some methods of food preservation.
Answer:

Pasteurization, Pickling, Freezing, etc.

Question 42. What are biofertilizers?
Answer:

Biofertilizers:

Biofertilizers are the microbes that can bring about the nutrient enrichment of soil and enhances the nutrient availability to crop plants. Example: Azotobacter, Azolla-anabaena, Rhizobium etc.

Question 43. Name two plant pathogenic fungi.
Answer:

Albugo Candida and Puccinia graminis.

Question 44. Name two algae that are used as food.
Answer:

Alaria and Laminaria.

Question 45. Name a virus that is used as a biopesticide.
Answer:

Nucleopolyhedrosin virus (NPV).

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