NCERT Solutions for Class 8 Science Chapter 2 Microorganisms: Friends or Foe-Ever wondered why a stale bread kept in the dark and humid area grows white colored mesh over it? Why you become sick and everybody around you says its viral? Why you prefer to drink water processed in RO and not that of the tap? How the milk with a little curd kept in a hotter place by your mother turn into curd next morning? All these questions have only one answer, it is due to the presence of microorganisms. The NCERT textbook class 8 Chapter 2 microorganisms friend and foe mainly deals with the role of microorganisms in our lives. After studying the chapter thoroughly you will be able to attempt the exercise of NCERT textbook and get correct NCERT solutions for class 8 science chapter 2 microorganisms - friend and foe.
Microorganisms are the smallest organisms that can not be seen with naked eyes. Now, must be wondering that if they can not be seen with naked eyes then how did we first get to know about them? It was mainly due to the invention of an instrument called the microscope. You will get to know about the structure and working of a microscope in NCERT grade 8 science chapter 2 microorganisms friends and foe.
There are five groups of microorganisms around us. These include
Among the above-given microorganisms, viruses are different from the rest. How? You will learn in class 8 science chapter 2.
Microorganisms can act as our friends by helping us in making of bread and curd, production of alcohol by fermentation, production of antibiotics, etc. They also help in agriculture by performing nitrogen fixation the details of which you will study in NCERT science chapter 2.
microorganisms can become our foes when they cause deadly diseases in humans such as tuberculosis, typhoid etc. How would you get to know which microorganisms are helpful and which are harmful to us? The details regarding this, are mentioned in NCERT grade 8 chapter 2 microorganisms: friend and foe.
This chapter also deals with topics such as food poisoning and its prevention. Once you have gone through this chapter, you will understand whether to consider microorganisms our friend or foe or both. You can also refer to NCERT solutions for Class 8 science chapter 2 microorganisms friend and foe.
2.2 Where do microorganisms live
2.3 Microorganisms and us
2.4 Harmful microorganisms
2.5 NItrogen fixation
2.6 Nitrogen cycle
After reading the above introduction to microorganisms, you can try solving NCERT class 8 Chapter 2 microorganisms worksheets. You can also attempt NCERT quizzes for science chapter 2. For the preparation of this chapter create your NCERT class 8 Chapter 2 notes by yourself. This will help you to learn better.
Since NCERT is the key to success, you can be well versed with NCERT with the help of NCERT Solutions for class 8 Science Ch 2. After studying NCERT and NCERT solutions, you will have NCERT at your fingertips and will be able to answer NCERT based questions. One example of such questions is given below
Q. Why do teachers keep telling us not to let water collect anywhere in our surroundings?
Ans. The teachers keep telling us to not let water collect anywhere because this water may act as a breeding site for insects that can cause diseases like dengue, malaria etc.
Q. The milk that comes in packets do not get spoiled because it is pasteurised. What do you understand by pasteurized milk?
Ans. The packeted milk is boiled at high-temperature for 15 to 30 seconds to kill the microbes present in it. This milk is called pasteurized milk and it does not get spoiled.
So, like these questions, you can solve more for examination purpose.
2. Tick the correct answer.
(c) Carrier of malaria-causing protozoan is
(i) female Anopheles mosquito (ii) cockroach
(iii) housefly (iv) butterfly
8. Write a short paragraph on the harmful effects of microorganisms.
4. Can microorganisms be seen with the naked eye? If not, how can they be seen?