Students may better prepare for the Class 10 board exams by using the material provided in the NCERT Solutions Science. This knowledge is extremely crucial as it assists students in better comprehending difficult subject matter. Checking how well you understand a certain subject by reading the solutions to the questions asked in the textbook is a great way to figure out where your knowledge is strongest and where it needs improvement. Our subject matter specialists have designed these NCERT Solutions for Class 10 Science in such a manner that the students will have a much better understanding of all of the subjects that are included in the curriculum for CBSE Class 10 Science.

Students are able to create a strong conceptual basis with the help of the NCERT Solutions PDFs available at SWC. This base plays a key part in the students’ preparation for the latter phases of the competitive examinations. We give comprehensive answers to challenges posed by NCERT in accordance with the methodology provided by CBSE. The students are able to effortlessly prepare all of the ideas that are presented in their respective courses better and more successfully, and they are even able to succeed in passing the most difficult competitive examinations, such as JEE Main, JEE Advanced, NEET, AIMS, and so on.

Your academic journey begins a new stage as you reach the eighth grade, and a new facet of learning awaits you. This is the year where pupils begin to acquire an interest in the topic at hand, and it is also the year in which you choose whether you will study business, humanity, or science in the following year (class 12). As a consequence of this, having a solid foundation of knowledge in fields such as mathematics and physics comes highly recommended. The NCERT textbook for class 8 is the greatest book now available on the market for enhancing one’s education in the areas of mathematics and science. Read up on the theory that is presented in the book for grade 8 and answer all of the questions that are posed in the practice section of the NCERT textbook.


Question 1. Fill in the blanks.

(a) Microorganisms can be seen with the help of a________________.

(b) Blue-green algae fix ______________ directly from air to enhance fertility.

(c) Alcohol is produced with the help of __________.

(d) Cholera is caused by ____________.

Solution :

(a) Microorganisms can be seen with the help of a microscope.

(b) Blue-green algae fix nitrogen directly from air to enhance fertility.

(c) Alcohol is produced with the help of yeast.

(d) Cholera is caused by bacteria.

Question 2. Tick the correct answer.

(a) Yeast is used in the production of

(i) Sugar

(ii) alcohol

(iii) hydrochloric acid

(iv) oxygen

(b) The following is an antibiotic

(i) Sodium carbonate

(ii) Streptomycin

(iii) Alcohol

(iv) Yeast

(c) Carrier of malaria-causing protozoan is

(i) Female Anopheles mosquito

(ii) cockroach

(iii) housefly

(iv) butterfly

(d) The most common carrier of communicable diseases is

(i) ant

(ii) housefly

(iii) dragonfly

(iv) spider

(e) The bread or idli dough rises because of

(i) heat

(ii) grinding

(iii) growth of yeast cells

(iv) kneading

(f) The process of conversion of sugar into alcohol is called

(i) nitrogen fixation

(ii) moulding

(iii) fermentation

(iv) infection.

Solution :

(a) —> (ii)

(b) —> (ii)

(c) —> (i)

(d) —> (ii)

(e) —> (iii)

(f) —> (iii)

Question 3. Match the organisms in Column A with their action in Column B.

Column IColumn II
(a) Bacteria(b) Rhizobium(c) Lactobacillus(d) Yeast(e) A protozoan(f) A virus(i) Fixing nitrogen(ii) Setting of curd(iii) Baking of bread(iv) Causing malaria(v) Causing cholera(vi) Causing AIDS

Solution :

Column IColumn II
(a) Bacteria(b) Rhizobium(c) Lactobacillus(d) Yeast(e) A protozoan(f) A virus(i) Causing cholera(ii) Fixing nitrogen(iii) Setting of curd(iv) Baking of bread(v) Causing malaria(vi) Causing AIDS

Question 4. Can microorganisms be seen with the naked eyes? If not, how can they be seen?

Solution : Micro-organisms are too small to be seen through naked eyes. They can be seen with the help of a magnifying glass or microscope.

For example, fungus that grows on bread is so small that it can be seen only with the help of a magnifying glass or microscope.

No, microorganisms cannot be seen with the naked eye. They can only be seen with the help of microscope.

Question 5. What are the major groups of microorganisms?

Solution : There are five major groups of micro-organisms:

→ Bacteria – They are single celled disease-causing micro-organisms. They can be spiral or rod- shaped.

→ Fungi – They are mostly multicellular disease-causing microbes. Bread moulds are common examples of fungi.

→ Protozoa – They mainly include organisms such as Amoeba, Plasmodium,etc. They can be unicellular or multicellular.

→ Virus -Viruses are disease-causing microbes that reproduce only inside the host organism.

→ Algae – They include multicellular, photosynthetic organisms such as Spirogyra, Chlamydomonas, etc.

Question 6. Name the microorganism which can fix atmospheric nitrogen in the soil.

Solution : Certain bacteria such as Rhizobium and blue green algae present in the soil fix atmospheric nitrogen and convert it into compounds of nitrogen.

Question 7. Write 10 lines on the usefulness of microorganisms in our lives.

Solution : Micro-organisms are too small to be seen through naked eyes. However, they are vital to plants and the environment.

1. Rhizobium present in the roots of pulse plants fix nitrogen from air and supply nitrogen compounds to the pulse plants.

2. Micro-organisms are also used in winemaking, baking, pickling, and other food making processes.

3. Alcoholic fermentation by yeast is widely used in the preparation of wine and bread.

4. Microbes are used to reduce pollution. For example, decomposers such as bacteria and fungi break down dead bodies and excreta to form inorganic compounds, which can be absorbed by plants.

5.Microbes also play an important role in the preparation of medicines. Antibiotics are chemicals produced by micro-organisms to kill bacteria. Penicilin is an antibotic made from Penicilium.

6. Bacteria present in our intestine helps in proper digestion and release Vitmain B which is absorbed by intestine.

7. Many vaccines are prepared from micro-organisms. These vaccines are given to children to protect them from disease.

8. Certain microbes are also used in the biological treatment of sewage and industrial effluents.

9.Yeast is used in making idlis, bhaturas, bread, pastries and cakes.

10.Lactobacillus is used to form curd from milk.

Question 8. Write a short paragraph on the harms caused by microorganisms.

Solution : The harm caused by microorganisms are as follows-

a. They cause many communicable diseases like cholera, common cold, tuberculosis etc.

b. Malaria is caused by a microorganism called plasmodium.

c. Several plants diseases are caused by bacteria and fungi.

d. Food poisoning is caused by microorganism.

e. They are responsible for spoiling of food.

Question 9. What are antibiotics? What precautions must be taken while taking antibiotics?

Solution : The medicines that kill or stop the growth of the disease-causing microorganism are called antibiotic. Streptomycin, tetracycline, erythromycin etc. are common antibiotics. They are manufactured by growing specific micro-organisms and are used to cure a variety of diseases.

Precautions to be taken while using antibiotics :

* Antibiotics should be taken under the supervision of a well qualified doctor.

* Course (intake) of antibiotics should be completed as per the prescription given by the doctor.

* Antibiotics should be taken in the right amount and at the right time. A wrong dose of antibiotics makes the drug ineffective. Also, excessive consumption of drugs may kill the useful bacteria present in our body.


Lacking a solid understanding of scientific principles might have unimaginable repercussions. The NCERT textbook for class 8 science comes highly recommended from a number of different educators. You will not only be able to improve your academic performance by using the appropriate combination of NCERT textbooks and NCERT answers for class 8 science chapter 2, but you will also be able to establish a strong foundation in science. The NCERT answers that were generated by the SWC team are among the finest solutions that are currently accessible on the web.

When working through the exercises in the NCERT textbook, if you run into any type of difficulty or uncertainty, you may use the swc NCERT Solutions for class 8 as a point of reference. While you are reading the theory form textbook, it is imperative that you always have notes prepared. You should make an effort to understand things from the very beginning so that you may create a solid foundation in the topic. Use the NCERT as your parent book to ensure that you have a strong foundation. After you have finished reading the theoretical section of the textbook, you should go to additional reference books.

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