Class 8th Biology AP Board Solution
Improve Your Learning- How do vaccines works in our body?
- What are the differences between Antibiotic and Vaccine?
- The invention of pencilline protected the world from deaths during the first world war,…
- Take three bowls and mark as A, B, C. Pour lukewarm milk in bowl A, hot milk in bowl B,…
- Collect more information about scientists who invented and discovered other facts related…
- Make an Album of scientists and their discoveries related to Microorganisms.…
- Visit the veterinary hospital and prepare a list of cattle diseases by asking questions to…
- What is pasteurisation? What is the use of it?
- How do you appreciate Edward Jenner's experiments?
- Visit a nearby milk chilling center. Observe the process and make a report on it. (40…
- ''Prevention is better than cure'' comment.
- Raheem tells to his neighbours, "stagnation of sewage in our surroundings is harmful to…
- Jeevan said that "If there are no microorganisms earth will remain with wastes" will you…
- Pranavi is suffering from serious illness. Doctor prescribed antibiotics for five days.…
- What are the precautions taken to eradicate malaria?
- One medical store owner is giving antibiotics to his customer who is suffering from fever…
- How do vaccines works in our body?
- What are the differences between Antibiotic and Vaccine?
- The invention of pencilline protected the world from deaths during the first world war,…
- Take three bowls and mark as A, B, C. Pour lukewarm milk in bowl A, hot milk in bowl B,…
- Collect more information about scientists who invented and discovered other facts related…
- Make an Album of scientists and their discoveries related to Microorganisms.…
- Visit the veterinary hospital and prepare a list of cattle diseases by asking questions to…
- What is pasteurisation? What is the use of it?
- How do you appreciate Edward Jenner's experiments?
- Visit a nearby milk chilling center. Observe the process and make a report on it. (40…
- ''Prevention is better than cure'' comment.
- Raheem tells to his neighbours, "stagnation of sewage in our surroundings is harmful to…
- Jeevan said that "If there are no microorganisms earth will remain with wastes" will you…
- Pranavi is suffering from serious illness. Doctor prescribed antibiotics for five days.…
- What are the precautions taken to eradicate malaria?
- One medical store owner is giving antibiotics to his customer who is suffering from fever…
Improve Your Learning
Question 1.How do vaccines works in our body?
Answer: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?
Answer:
Question 3.The invention of pencilline protected the world from deaths during the first world war, explain.
Answer: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.
Answer: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.
Answer: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.
Answer: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?
Answer: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
Question 8.What is pasteurisation? What is the use of it?
Answer:Pasteurisation is a method of preservation of milk. In this firstly milk is boiled at a temperature 70°C for 15 to 30 seconds and then suddenly chilled and stored at low temperatures. Due to this growth of microorganisms are prevented.
Use of Pasteurisation- Due to pasteurization growth of microorganisms is prevented and thus they help in storage of milk for a longer period. Pasteurisation prevents spoilage of milk.
Question 9.How do you appreciate Edward Jenner's experiments?
Answer:Contribution of Edward Jenner is remarkable. Experiments of Edward Jenner led to the discovery of vaccines.
He was the first one to give the concept of vaccination and as we know due to vaccination only we are protected from many diseases.
Also at the time of discovery of vaccination by Edward Jenner, this was a great discovery because at that time many people were suffering from small pox and his discovery saved the lives of many people.
So, Edward Jenner’s experiments are highly appreciable because due to his experiments only vaccination was introduced which is only cure for many diseases.
Question 10.Visit a nearby milk chilling center. Observe the process and make a report on it. (40
Answer:Pasteurisation is the process which was observed in the milk chilling center. In this process firstly milk was heated at temperatures up to 70°C for 15 to 30 seconds and are then chilled and stored at low temperatures.
It was told by the owner of milk chilling center this is the process that they use for long storage of milk and this process prevents the growth of microorganisms and thus prevent spoilage of milk.
Question 11.''Prevention is better than cure'' comment.
Answer:It is very truly said that “Prevention is better than cure” due to following reasons:
● When a person suffers from a disease it affects functioning of many organs of the person and even it is not sure that person will recover in case of deadly disease. Therefore, it is always better to prevent diseases.
● Secondly, since treatment takes time it affects the person at both mental and financial level. A great time get wasted during that period.
● Also, in the case of communicable disease, the person becomes the source which communicates disease to other person and thus affects the lives of others.
Due to the above-mentioned reasons, it is always better to prevent the disease than a cure.
Question 12.Raheem tells to his neighbours, "stagnation of sewage in our surroundings is harmful to our health." Do you support this? Why?
Answer:Yes, I support Raheem because stagnation of sewage in our surroundings led to growth of many disease-causing microorganisms. Stagnation of sewage provides a favorable environment to the disease-causing microorganisms and they start growing there in large number and act as a great threat to our life.
Also, many other organisms like housefly who keep roaming in our homes sit on that sewage and then on our foods and other things and thus cause different diseases.
So, Raheem is very correct that stagnation of sewage is harmful to our health.
Question 13.Jeevan said that "If there are no microorganisms earth will remain with wastes" will you agree this statement, why?
Answer:Yes, I agree to the statement of Jeevan that “if there are no microorganisms earth will remain with wastes.”
There are many microorganisms which are saprophytes and live on the dead organic matter. They cause degradation and decomposition of those waste materials and convert those complex organic substances into simpler inorganic substances and thus clean the earth.
If there will be no microorganisms there will be no decomposition, degradation, and conversion of complex organic substances into simpler inorganic substances and wastes keep on accumulating everywhere and in this way our earth will become dirty.
So, Presence of microorganisms is quite essential for cleaning of the earth surface.
Question 14.Pranavi is suffering from serious illness. Doctor prescribed antibiotics for five days. After three days of usage she stopped taking antibiotics. Is it right or not, discuss.
Answer:It is not right on part of Pranavi to stop taking antibiotics by herself as she is suffering from serious illness and doctor has prescribed her antibiotics for five days.
We should always complete the dose prescribed by the doctor because when we do not complete the dose chance of acquiring the disease again becomes more and also complete dosage kills the disease-causing microorganisms in our body while incomplete dosage only weakens them.
Therefore, in the case of incomplete dosage chance of acquiring the same disease becomes more. So, in order to avoid the disease again, complete dosage should be taken by us prescribed by the doctor.
So, it is not right on the part of Pranavi to stop taking antibiotics in between because due to this chances of her becoming ill again increase.
Question 15.What are the precautions taken to eradicate malaria?
Answer:Following precautions need to be taken to avoid malaria:
● Stagnation of water needs to be avoided because stagnant water provides favorable environment to the mosquitoes to grow.
● Mosquito nets should be used to prevent entry of mosquitoes.
● Mosquito repelling sprays should be sprayed from time to time.
● Mosquito avoiding creams should be applied to the body before going to sleep and should wear full sleeves cloth.
● Doors and windows need to be closed in the evening time in order to avoid entry of mosquitoes.
Question 16.One medical store owner is giving antibiotics to his customer who is suffering from fever without a doctor’s prescription? But the customer's daughter Malathi is telling her father not to take antibiotics without doctor’s prescription. Whom do you support and why?
Answer:I will support Malathi as she is true that her father should not take antibiotics without doctor’s prescription.
Taking antibiotics without doctor’s prescription can be harmful for us because it can even kill essential microorganisms present in our body. Also, antibiotics affect our blood cells which fight with the disease causing organisms. Taking of unnecessary antibiotics increase resistance in our body and due to which disease causing organisms are not killed in our body when we take them because our body becomes resistant to those antibiotics.
So, we should always take antibiotics on doctor’s prescription as they prescribe antibiotics only when they are needed and in proper dosage due to which no harm is caused to our body.
How do vaccines works in our body?
Answer:
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?
Answer:
Question 3.
The invention of pencilline protected the world from deaths during the first world war, explain.
Answer:
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.
Answer:
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.
Answer:
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.
Answer:
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?
Answer:
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
Question 8.
What is pasteurisation? What is the use of it?
Answer:
Pasteurisation is a method of preservation of milk. In this firstly milk is boiled at a temperature 70°C for 15 to 30 seconds and then suddenly chilled and stored at low temperatures. Due to this growth of microorganisms are prevented.
Use of Pasteurisation- Due to pasteurization growth of microorganisms is prevented and thus they help in storage of milk for a longer period. Pasteurisation prevents spoilage of milk.
Question 9.
How do you appreciate Edward Jenner's experiments?
Answer:
Contribution of Edward Jenner is remarkable. Experiments of Edward Jenner led to the discovery of vaccines.
He was the first one to give the concept of vaccination and as we know due to vaccination only we are protected from many diseases.
Also at the time of discovery of vaccination by Edward Jenner, this was a great discovery because at that time many people were suffering from small pox and his discovery saved the lives of many people.
So, Edward Jenner’s experiments are highly appreciable because due to his experiments only vaccination was introduced which is only cure for many diseases.
Question 10.
Visit a nearby milk chilling center. Observe the process and make a report on it. (40
Answer:
Pasteurisation is the process which was observed in the milk chilling center. In this process firstly milk was heated at temperatures up to 70°C for 15 to 30 seconds and are then chilled and stored at low temperatures.
It was told by the owner of milk chilling center this is the process that they use for long storage of milk and this process prevents the growth of microorganisms and thus prevent spoilage of milk.
Question 11.
''Prevention is better than cure'' comment.
Answer:
It is very truly said that “Prevention is better than cure” due to following reasons:
● When a person suffers from a disease it affects functioning of many organs of the person and even it is not sure that person will recover in case of deadly disease. Therefore, it is always better to prevent diseases.
● Secondly, since treatment takes time it affects the person at both mental and financial level. A great time get wasted during that period.
● Also, in the case of communicable disease, the person becomes the source which communicates disease to other person and thus affects the lives of others.
Due to the above-mentioned reasons, it is always better to prevent the disease than a cure.
Question 12.
Raheem tells to his neighbours, "stagnation of sewage in our surroundings is harmful to our health." Do you support this? Why?
Answer:
Yes, I support Raheem because stagnation of sewage in our surroundings led to growth of many disease-causing microorganisms. Stagnation of sewage provides a favorable environment to the disease-causing microorganisms and they start growing there in large number and act as a great threat to our life.
Also, many other organisms like housefly who keep roaming in our homes sit on that sewage and then on our foods and other things and thus cause different diseases.
So, Raheem is very correct that stagnation of sewage is harmful to our health.
Question 13.
Jeevan said that "If there are no microorganisms earth will remain with wastes" will you agree this statement, why?
Answer:
Yes, I agree to the statement of Jeevan that “if there are no microorganisms earth will remain with wastes.”
There are many microorganisms which are saprophytes and live on the dead organic matter. They cause degradation and decomposition of those waste materials and convert those complex organic substances into simpler inorganic substances and thus clean the earth.
If there will be no microorganisms there will be no decomposition, degradation, and conversion of complex organic substances into simpler inorganic substances and wastes keep on accumulating everywhere and in this way our earth will become dirty.
So, Presence of microorganisms is quite essential for cleaning of the earth surface.
Question 14.
Pranavi is suffering from serious illness. Doctor prescribed antibiotics for five days. After three days of usage she stopped taking antibiotics. Is it right or not, discuss.
Answer:
It is not right on part of Pranavi to stop taking antibiotics by herself as she is suffering from serious illness and doctor has prescribed her antibiotics for five days.
We should always complete the dose prescribed by the doctor because when we do not complete the dose chance of acquiring the disease again becomes more and also complete dosage kills the disease-causing microorganisms in our body while incomplete dosage only weakens them.
Therefore, in the case of incomplete dosage chance of acquiring the same disease becomes more. So, in order to avoid the disease again, complete dosage should be taken by us prescribed by the doctor.
So, it is not right on the part of Pranavi to stop taking antibiotics in between because due to this chances of her becoming ill again increase.
Question 15.
What are the precautions taken to eradicate malaria?
Answer:
Following precautions need to be taken to avoid malaria:
● Stagnation of water needs to be avoided because stagnant water provides favorable environment to the mosquitoes to grow.
● Mosquito nets should be used to prevent entry of mosquitoes.
● Mosquito repelling sprays should be sprayed from time to time.
● Mosquito avoiding creams should be applied to the body before going to sleep and should wear full sleeves cloth.
● Doors and windows need to be closed in the evening time in order to avoid entry of mosquitoes.
Question 16.
One medical store owner is giving antibiotics to his customer who is suffering from fever without a doctor’s prescription? But the customer's daughter Malathi is telling her father not to take antibiotics without doctor’s prescription. Whom do you support and why?
Answer:
I will support Malathi as she is true that her father should not take antibiotics without doctor’s prescription.
Taking antibiotics without doctor’s prescription can be harmful for us because it can even kill essential microorganisms present in our body. Also, antibiotics affect our blood cells which fight with the disease causing organisms. Taking of unnecessary antibiotics increase resistance in our body and due to which disease causing organisms are not killed in our body when we take them because our body becomes resistant to those antibiotics.
So, we should always take antibiotics on doctor’s prescription as they prescribe antibiotics only when they are needed and in proper dosage due to which no harm is caused to our body.
