Test: Microorganisms Friend And Foe - 1


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This mock test of Test: Microorganisms Friend And Foe - 1 for Class 8 helps you for every Class 8 entrance exam. This contains 10 Multiple Choice Questions for Class 8 Test: Microorganisms Friend And Foe - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Microorganisms Friend And Foe - 1 quiz give you a good mix of easy questions and tough questions. Class 8 students definitely take this Test: Microorganisms Friend And Foe - 1 exercise for a better result in the exam. You can find other Test: Microorganisms Friend And Foe - 1 extra questions, long questions & short questions for Class 8 on EduRev as well by searching above.
QUESTION: 1

Microbiology is the study of :

Solution:

Microbiology is the study of all living organisms that are too small to be visible with the naked eye. This includes bacteria, archaea, viruses, fungi, prions, protozoa and algae, collectively known as 'microbes'

QUESTION: 2

What did Leeuwenhoek observe in a drop of pond water?

Solution:

Leeuwenhoek observed large number of living microorganisms in a drop of water when observed under microscope. These organisms are not visible by naked eyes

QUESTION: 3

 The bacterium present in curd is:

Solution:

Lactobacillus is the microorganism present in curd. This bacterium converts milk into curd at 30oC to 40oC.

QUESTION: 4

Rhizobium bacteria

Solution:

Rhizobium is a bacteria found in soil that helps in fixing nitrogen in leguminous plants. It attaches to the roots of the leguminous plant and produces nodules. These nodules fix atmospheric nitrogen and convert it into ammonia that can be used by the plant for its growth and development.

QUESTION: 5

 _______ are the agents that act as carriers of a pathogen and spread diseases.

Solution:

Animals or insects carry infecting agents from a sick person to another potential host. These animals are thus the intermediaries and are termed as vectors. The most common vectors are mosquitoes.

QUESTION: 6

Which one of the following is not a method of food preservation?

Solution:

Salt is effective as a preservative because it reduces the water activity of foods. Adding salt to foods can also cause microbial cells to undergo osmotic shock, resulting in the loss of water from the cell and thereby causing cell death or retarded growth.

Boiling or blanching food at high temperatures destroys all enzyme activity and almost all microorganisms. The more acidic the food, such as fruit, the more easily microorganisms are destroyed by heat. Boiled preserves must be sealed in airless conditions (e.g. airtight jars) to prolong their shelf life.

Drying or “dehydrating” food is a method of food preservation that removes enough moisture from the food so bacteria, yeast and molds cannot grow.

Pickling is defined as the process of preserving a food by either anaerobic fermentation in brine or immersion in vinegar. The resulting food is called a pickle. Pickling can add a special flavor to food by themselves or mixed in with other foods.

QUESTION: 7

The microorganism which helps in fermentation is :

Solution:

Fermentation is the process in which yeasts convert sugar into ethanol in the absence of oxygen. The fermentation process is used to produce alcoholic beverages.

QUESTION: 8

Agents in infectious diseases responsible are called

Solution:

There are five major types of infectious agents: bacteria, viruses, fungi, protozoa, and helminths. In addition, a new class of infectious agents, the prions, has recently been recognized.

QUESTION: 9

Which two words are synonyms?

Solution:

Microorganism and microbe are two words having same meaning, very small organisms that cannot be seen with naked eyes. So, microorganism and microbe are synonyms.

QUESTION: 10

A plant disease called citrus canker is caused by a _________ .

Solution:

 Citrus canker is a plant disease caused by bacteria. It’s mode of transmission is through air.

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