Class 10 English Chapter 4 Louis Pasteur, Conqueror of Disease

Comprehension I:

Question 1.
“Louis Pasteur was not a soldier, but he was a fighter.” What does the statement mean?

Answer:
Though Louis Pasteur did not join the army and become a soldier, he was a fighter because he fought various kinds of diseases through his discoveries about bacteria.

Question 2.
What are bacteria?

Answer:
Bacteria are vegetable organisms – little rod-shaped plants which exist in the air, water and soil, and in the bodies of animals and plants; some but not all are the causes of diseases; some convert matter into food for plants.

Question 3.
As a scientist, how was Louis Pasteur unique?

Answer:
Louis Pasteur not only made some exciting discoveries about germs but he was also able to use his discoveries in very practical ways. He could help many people running various industries in France.

Question 4.
How did Pasteur try to solve difficult problems?
Answer:
Pasteur used to sit for hours, quite silent and motionless, thinking hard about the difficult problems.

Question 5.
How would Pasteur react whenever he solved a problem?
What does this reveal about him as a person?

Answers:
When he thought of a solution, his kind, tired-looking face would brighten with pleasure and excitement, and he would rush around to tell his discovery to his wife and to others who were helping him.
This shows that Pasteur was sincere about solving problems and was also very simple and childlike in sharing his discoveries with others.

Question 6.
What discoveries did Pasteur make about yeast?

Answer:
Yeast is used to make the beer foam. Pasteur discovered that yeast was alive, made up of tiny living cells. When these cells were healthy, the yeast acted well, but if they were diseased, the yeast and the beer went wrong.

Question 7.
What does ‘spontaneous generation’ mean?

Answer:
Some scientists believed in ‘spontaneous generation’, i.e., they believed that germs had no parents but just occurred by themselves.

Question 8.
Did Pasteur believe in Spontaneous generation? If not, what did he believe in?
Answer:
Pasteur and some scientists like him believed that germs were carried in the air and might infect other things that came in contact with them.

Question 9.
In the statement, “Pasteur proved that he was right” (Para 9), What did he prove?
Answer:
Pasteur proved that germs were carried in the air and might infect other things that came in contact with them.

Question 10.
In the second soup experiment (para 10) which soup was the worst, which was the best and which one was better?

Answer:
In the second soup experiment, the bottles opened in the hotel bedroom were full of soup which had gone completely mouldy due to the presence of many germs; the bottles opened in the field were mouldy, but not quite so bad; those opened on the mountain had no germs in them at all. The last batch was the best, the first one was the worst, and the second one was better than the first one.

Question 11.
What is Pasteurization?

Answer:
Pasteurization is the process of heating wine milk or any other liquid to a temperature of 50 to 60 degrees centigrade to make the germs harmless. Pasteurized milk is milk which has been treated in this way and then sealed to prevent more germs from entering.

Question 12.
The writer says,” It would be impossible to imagine Pasteur experimenting with explosives or poisonous gas” (para 13). What quality of Pasteur is highlighted here?

Answer:
Pasteur’s love for mankind and his compassionate nature are highlighted in the sentence. He had no love for plain achievement, money or fame.

Question 13.
On what study did Pasteur spend all his time and energy for three years?

Answer:
For three years, Pasteur spent all his time and energy in tracking down the cause of a disease which had ruined the silkworm industry.

Question 14.
How is vaccination different from inoculation?

Answer:
Introducing live organisms into the body to generate immunity is vaccination (for viral diseases like smallpox, rubella, chicken-pox, measles, and tuberculosis) whereas introduction of weak or dead organisms into the body to produce immunity is called inoculation (for bacterial diseases like typhoid, diphtheria and cholera).

Question 15.
What made Pasteur believe that a cow could not have anthrax twice?
Answer:
When Pasteur was trying to discover a cure for the terrible disease called ‘Anthrax’, he found out, first of all, that a cow could not have Anthrax twice.

Question 16.
What made many scientists angry? (para 16)

Answer:
Pasteur began to wonder whether it would not be possible to make a cow and even a man just a little ill with Anthrax so that they might not get it again. He thought that this could be done by giving the cows or sheep very weak old germs to make them safe or immune for the future. This idea of giving animals germs made many scientists angry.

Question 17.
What is rabies?

Answer:
Rabies is a dangerous disease of dogs and other mammals, caused by a virus that can be transmitted through the saliva to humans, causing madness and convulsions.

Question 18.
How was Pasteur a better scientist than Jenner?

Answer:
Although Dr. Jenner had already discovered how to vaccinate against smallpox, he did not understand about bacteria. Pasteur after giving his life to this study was able to prove the value of inoculation and to find out ways of varying it for different diseases.

Question 19.
How was the very low death rate among the troops during the First World War a great tribute to Pasteur’s work?

Answer:
During the First World War 1 (1914-1918), the troops going abroad were » inoculated against such diseases as typhoid and enteric fever, and the very low death rate from this illness among the troops, even in unhealthy places, was a great tribute to Pasteur’s work.

Question 20.
At the opening ceremony of Pasteur Institute in Paris, Pasteur talked about two opposing laws.
Which are the two laws?
Which one did he favour?

Answers:
One law was a law of blood and death, opening out each day new methods of destruction, forcing nations to be always ready for battle; the second law was a law of peace, work, and health, whose only aim was to deliver f man from the disasters which surrounded I him. The first one seeks violent conquests and the other relief from mankind.

Pasteur favoured the second law of peace, work, and health because he was sure that science in obeying the law of humanity, will always labour to enlarge the frontiers of life.

Question 21.
What was his message to young students on the occasion of his 70th birthday celebration?

Answer:
His message was: “First ask yourselves, ‘What have I done for my education?’ Then as you advance in life, What have I done for my country?’ so that someday that supreme happiness may come to you, the consciousness of having contributed in some measure to the progress and welfare of humanity.”

Question 22.
What is the supreme happiness he talks about?

Answer:
He says supreme happiness is the result of the consciousness of having contributed in some measure to the progress and welfare of humanity.

Question 23.
Here are Louis Pasteur’s thoughts at various points in the lesson. Read the paragraphs mentioned against each and explain how he came to each conclusion.
a. I am certain that yeast is alive, made up of tiny living cells (para 7) ______

Answer:
While helping the brewer, Pasteur learned many things about yeast. He observed that yeast was alive, made up of tiny living cells. When these cells were healthy, the yeast acted well, but if they were diseased, the yeast and the beer went wrong.

b. Germs are carried in the air and may ______ infect other things that came in contact ______ with them, (para 8, 9)

Answer:
As Director of Scientific Studies at a famous college in Paris, Pasteur was thinking about decay and yeast and germs. He believed that germs were carried in the air and infected other things that came in contact with them. He proved this point by pulling out the neck of soup bottles so that there was a big bend in the middle.

The soup in the bottle never went bad because there were no parent germs in the soup and no germs could reach it because of the bend in the long tube. It was only when a little soup was split down the tube that germs entered it with dust and infected it.

c. Pure air is different from stale air (para 10) ______

Answer:
Pasteur filled some bottles with soup. He took some into a little hotel bedroom where the air was hardly ever changed, broke their necks off so that the air could enter freely, and after a few minutes sealed them up again. He then took some bottles into a field nearby and did the same with them.

Finally, he opened some on the top of a high mountain and again sealed them up. When they were examined, the bottles opened in the hotel bedroom were full of soup which had gone completely mouldy; the bottles opened in the field were mouldy, but, not quite so bad; those opened on the mountain had no germs in them at all.

d. Pasteurization makes the germs harmless, (para 12) ________

Answer:
Pasteur showed that by heating the wine or milk or whatever it might be to a temperature of 50 or 60 degrees centigrade, the germs were made harmless.

Comprehension II:

Question 1.
‘Do germs form from other germs, or do they just come of themselves?’

a) What did people like Pasteur believe about germs?
Answer:
People like Pasteur believed that germs were carried in the air and might infect other things that came in contact with them.

b) Which of the two was called ‘spontaneous generation’?

Answer:
Scientists other than Pasteur believed in ‘spontaneous generation’, i.e., they believed that germs had no parents but just occurred by themselves.

c) How did Pasteur prove that he was right?

Answer:
Pasteur proved that he was right by conducting an experiment in which the neck of a bottle with the soup was extended to prevent germs from entering. Only when the soup was poured into this bend, did it come in contact with germs from dust and get infected.

Question 2.
‘If you can cure animals, you can cure my son’.

a) What had Pasteur cured the animals of?
Answer:
Pasteur had cured the animals of the terrible disease of Anthrax.

b) What was wrong with the ‘son’ referred to?
Answer:
The boy was covered with bites from a mad dog and was sure to die.

c) Did Pasteur cure the boy? How?
Answer:
Pasteur inoculated the boy with some weak rabies germs and the boy recovered.

Comprehension III:

Question 1.
What was troubling the French wine growers? How did Pasteur solve their problem? What is the name of the process which was the solution to the wine-growers?
Answer:

• French wine growers troubled by a germ.
• Pasteur showed how to render these germs harmless.
• This process was called ‘Pasteurization’.

Some French wine growers faced a problem with a germ that was spoiling their wine. Pasteur demonstrated that heating the wine to a temperature of 50 or 60 degrees Celsius could neutralize these harmful germs. This method of treating the wine is known as ‘Pasteurization’.

Question 2.
How did Pasteur develop the idea of immunity?
Answer:

• Pasteur was busy discovering a cure for Anthrax.
• He found that a cow could not get it twice.
• He thought of giving weak old germs to make beings safe from Anthrax.

Pasteur was researching a cure for anthrax, a severe disease affecting cows and sheep in France and sometimes transmitted to humans through infected shaving brushes. He discovered that a cow could not contract anthrax twice. This led him to consider whether inducing a mild form of the disease with weakened germs could make the animals—and potentially humans—immune to future infections.

Question 3.
What human qualities of Pasteur do you admire?

Answer:
• All of Pasteur’s work was meant to help human beings.
• He was genuinely interested in ’ others’ problems.
• He was childlike and simple by nature.

Louis Pasteur was truly an ‘all-round’ scientist, dedicating his research to benefiting humanity. His focus was always on positive and life-affirming solutions rather than harmful experiments, such as explosives or poison gas. Pasteur’s genuine interest in addressing the problems of others was evident in his approach: he would contemplate issues deeply, and upon discovering a solution, he would eagerly share his findings with others.

Despite his significant contributions, Pasteur remained modest and childlike in his nature. For example, during a grand medical Congress in London, he was surprised by the applause, believing it was meant for someone of royal status rather than himself.

Question 4.
“All the research which he did in his laboratories was meant to help his fellow human beings”. Elucidate.
Answer:

• Pasteur discovered many things about germs and also used that knowledge well. ‘
• He worked hard in his laboratories to help people with specific problems.
• He discovered ‘inoculation’.

Pasteur not only made some exciting discoveries about germs but he was also able to use his discoveries in very practical ways. He worked hard in his laboratory with test tubes and all kinds of experiments, but nearly all the time he was working to help people who were suffering in some special way from the disease.

Among the people whom Pasteur was able to help were brewers, breeders of silk works, and cowkeepers, all of whom were trying to carry on important industries in France. He discovered ‘inoculation’ which provided immunity to people and animals against anthrax and also the dreaded disease, rabies.

Question 5.
What would have been the fate of humankind if Louis Pasteur had not discovered a vaccine against rabies? Answer: 

• Rabies is a dangerous disease.
• Many people used to die of rabies.
• Pasteur inoculated an infected boy.

Rabies is a dangerous disease of dogs and other mammals, caused by a virus that can be transmitted through the saliva to humans, causing madness and convulsions. Many people used to die of rabies. Many others used to suffer from bites caused by a mad dog.

Pasteur inoculated an infected boy with some weak rabies germs and the boy recovered. This turned the fate of rabies-infected people.

Louis Pasteur, Conqueror of Disease