Story Of Micro Organisms-2 Class 8th Biology AP Board Solution

Class 8th Biology AP Board Solution

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Question 1.

How do vaccines works in our body?


Vaccines contain weakened microorganisms which are able to cause disease but not upto very extreme level which can cause great harm to the body.

Since vaccines cause the disease they enable our bodies to release antibodies which fight with the disease causing microorganisms. Antibodies have a memory of diseases which occur once. So, due to vaccines antibodies get formed in our body for the respective disease and if in future we get infected by those disease antibodies present in our body due to vaccines attack the disease and we get a cure in short period of time.

In this way, vaccines protect us from very harmful effects of various diseases.

Question 2.

What are the differences between Antibiotic and Vaccine?


Question 3.

The invention of pencilline protected the world from deaths during the first world war, explain.


During the First World War many soldiers died due to bacterial infection.

Dr. Alexander Fleming was an army doctor at that time and was working on antibiotics in his laboratory. One day he found that there was some growth of fungi (mould) which was preventing the growth of the bacteria. He tested that fungi and found that it also killed other bacteria and that fungi were Penicillium notatum.

After this discovery fungi Penicillium notatum was used as antibiotic (substances that kill bacteria) namely penicillin to cure the infections of the soldiers with infected wounds due to bacteria.

Since, use of penicillin as antibiotic helped in curing the bacterial infections many deaths were prevented during First World War.

Question 4.

Take three bowls and mark as A, B, C. Pour lukewarm milk in bowl A, hot milk in bowl B, cold milk in bowl C. Add one tea spoon of curd or butter milk in three bowls and stir them slightly. Cover the bowls with lids. Keep the bowls undisturbed for five to six hours. In which bowl milk turned into curd? Give your reasons.


The milk will be turned into curd in bowl A and not in other bowls.

Explanation: Lactobacillus is the bacteria required for the formation of curd and it requires an appropriate temperature for its growth. Lukewarm milk not being very much cool and hot provides that appropriate temperature and hence lukewarm milk get converted into milk.

But bowl B and C contains hot and cold milk which do not provide appropriate temperature for the growth of bacteria due to which bacteria doesn’t grow in them and they are not converted into curd.

Question 5.

Collect more information about scientists who invented and discovered other facts related to Microorganisms. How these discoveries helped mankind? Make a chart presentation and paste it on your classroom wall Magazine.


Microbiology is the field of science which deals with the microorganisms and related aspects. This field involves the contribution of many scientists who started working in this field many years back.

In order to collect information about microbiologists or scientists contributed in these fields authentic and famous books of microbiology like Prescott, Pelczar needs to be referred. Other source can be internet where it can be studied that how study about microorganisms had evolved with new discoveries and facts and how this discoveries had affected human life.

Later on notes can be prepared about those scientists which can be presented over chart including highlighted information of remarkable discoveries in this field like role of Alexander Fleming who discovered antibiotics etc.

Question 6.

Make an Album of scientists and their discoveries related to Microorganisms.


In this an album can be prepared by taking photographs of scientists with major discoveries along with little description of their discovery.

The album can be prepared year wise which will help you to know that how studies about microorganisms had evolved. Secondly along with scientists’ picture some pictures related to their work can also be fixed in album.

Other way of preparing album is to devote a single page of album to each scientist where you can have description of particular scientist and their discovery.

In this way an album can be prepared.

Question 7.

Visit the veterinary hospital and prepare a list of cattle diseases by asking questions to the doctor?


After a visit to veterinary hospital I found that the cattle suffer from following diseases:

● Anthrax

● Foot and mouth diseases

● Viral diseases in prawns

● Ringworm