8th Grade > Biology
MICROORGANISMS FRIEND AND FOE MCQs
Total Questions : 49
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Answer: Option B. -> Bacteriophage
:
B
Abacteriophageis a type of virus that infects bacteria. In fact, the word "bacteriophage" literally means "bacteria eater," becausebacteriophagesdestroy their host cells.
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B
Abacteriophageis a type of virus that infects bacteria. In fact, the word "bacteriophage" literally means "bacteria eater," becausebacteriophagesdestroy their host cells.
Answer: Option A. -> True
:
A
Fermentation is a process by which carbohydrates are changed into alcohols and carbon dioxide by bacteria or yeast under anaerobic conditions.
Fermentation also involves the conversion of milk sugar (lactose) by Lactobacillus toproducelactic acid. These bacteriadenaturemilk protein(casein) so that they clump together to form curd.
:
A
Fermentation is a process by which carbohydrates are changed into alcohols and carbon dioxide by bacteria or yeast under anaerobic conditions.
Fermentation also involves the conversion of milk sugar (lactose) by Lactobacillus toproducelactic acid. These bacteriadenaturemilk protein(casein) so that they clump together to form curd.
Answer: Option C. -> Both the statements are correct.
:
C
Viruses are infectious entity which are seemingly aliveonly inside a host cell.
They are non-living outside the living cell. They are composed of genetic material (DNA or RNA) but never both enclosed within a protein coat called capsid. Theylackcellular organisation due to the absence of cell organelles, plasma membrane, etc. Viruses cause many infectious diseases includingpolio, herpes and common cold.
:
C
Viruses are infectious entity which are seemingly aliveonly inside a host cell.
They are non-living outside the living cell. They are composed of genetic material (DNA or RNA) but never both enclosed within a protein coat called capsid. Theylackcellular organisation due to the absence of cell organelles, plasma membrane, etc. Viruses cause many infectious diseases includingpolio, herpes and common cold.
Answer: Option B. -> Lactobacillus
:
B
Lactobacillus is the microorganism present in curd. This bacterium converts milk into curd at 30 to 40oC.
:
B
Lactobacillus is the microorganism present in curd. This bacterium converts milk into curd at 30 to 40oC.
Answer: Option D. -> pathogens
:
D
Pathogens is the term given for harmful disease-causing microorgansims. They can enter our body through contaminated air, water or food. They can also get transmitted by direct contact with an infected person or carried through an animal. Bacteria, fungi, protozoa, etc are examples of microorganisms that can be pathogens.
:
D
Pathogens is the term given for harmful disease-causing microorgansims. They can enter our body through contaminated air, water or food. They can also get transmitted by direct contact with an infected person or carried through an animal. Bacteria, fungi, protozoa, etc are examples of microorganisms that can be pathogens.
Answer: Option A. -> True
:
A
Boiling is an important method of making food contaminant-free. Boiling food kills the microbes present in the food. When food is boiled at high temperatures, microbes present cannot survive in those conditions.
:
A
Boiling is an important method of making food contaminant-free. Boiling food kills the microbes present in the food. When food is boiled at high temperatures, microbes present cannot survive in those conditions.
Answer: Option C. -> Aedes mosquito
:
C
Dengue is caused by a virus and is spread by a species of mosquito called Aedes. The spread of this disease can beprevented by using mosquito nets, repellents and by control of breeding of mosquitoes by not allowing water stagnation in our surroundings.
:
C
Dengue is caused by a virus and is spread by a species of mosquito called Aedes. The spread of this disease can beprevented by using mosquito nets, repellents and by control of breeding of mosquitoes by not allowing water stagnation in our surroundings.
Answer: Option A. -> True
:
A
Fermentation is the natural process in which sugars are converted to alcohol by yeast. Carbon dioxide is also released in this reaction as a byproduct. This process is used in distilleries (alcohol industries) for the production of wine, beerand spirits.
:
A
Fermentation is the natural process in which sugars are converted to alcohol by yeast. Carbon dioxide is also released in this reaction as a byproduct. This process is used in distilleries (alcohol industries) for the production of wine, beerand spirits.
Answer: Option C. -> Weak microorganisms
:
C
A vaccine is abiological preparation containing weakened or dead microbes. It is introduced into a healthy person's body so that it can produce antibodies against the disease-causing microbes. Vaccines can be injected or administered orally.
:
C
A vaccine is abiological preparation containing weakened or dead microbes. It is introduced into a healthy person's body so that it can produce antibodies against the disease-causing microbes. Vaccines can be injected or administered orally.
Answer: Option A. -> resistance in bacteria against that antibiotic
:
A
Antibiotics are chemicals that can kill or retard the growth of other harmful microbes. If the disease causing bacteria is exposed to excess, unnecessary or incomplete dosage of antibiotic, then the surviving population of pathogens may begin to develop resistance against the antibiotic.
:
A
Antibiotics are chemicals that can kill or retard the growth of other harmful microbes. If the disease causing bacteria is exposed to excess, unnecessary or incomplete dosage of antibiotic, then the surviving population of pathogens may begin to develop resistance against the antibiotic.