THE EVER-EVOLVING WORLD OF SCIENCE : Class 7 : Science : Question Answers
Science is not fixed but keeps growing with time. From the discovery of fire and the invention of the wheel, science has been guiding human progress. Ancient discoveries like the telescope and microscope opened the doors of knowledge, while inventions such as electricity, machines, and vaccines improved human life.
Great scientists like Galileo, Newton, Edison, and Einstein made important contributions that changed the way we live. Today, science touches every part of our life — communication, transport, medicine, agriculture, industries, and even space research.
The chapter also teaches us that science should be used for the welfare of humanity, not for destruction. It is an ever-evolving journey that continues to shape our past, present, and future.
SHORT QUESTION AND ANSWER
1. What is science?
Science is the study of nature and the development of knowledge through observation, experiments, and reasoning.
2. Why is science called “ever-evolving”?
Because it keeps developing with new discoveries and inventions.
3. Name two early scientific discoveries by humans.
Discovery of fire and invention of the wheel.
4. What did the invention of the wheel lead to?
It led to the development of transport.
5. Who invented the telescope?
Galileo Galilei.
6. What is the use of the telescope?
It is used to observe distant objects in the sky.
7. Who invented the microscope?
Anton van Leeuwenhoek (simple microscope).
8. What is the use of the microscope?
It is used to observe very small objects not visible to the naked eye.
9. Name one scientist who discovered the laws of motion.
Sir Isaac Newton.
10. What did Thomas Edison invent?
The electric bulb.
11. Who gave the theory of relativity?
Albert Einstein.
12. What are vaccines?
Medicines that protect us from diseases.
13. Who discovered the vaccine for smallpox?
Edward Jenner.
14. Why is electricity important?
It is used in homes, industries, and almost every field of life.
15. Give two examples of modern communication systems.
Mobile phones and the internet.
16. How has science helped agriculture?
By providing new machines, irrigation methods, and high-yield seeds.
17. How has science helped medicine?
By developing vaccines, antibiotics, and advanced treatments.
18. Name one Indian scientist who contributed to physics.
C. V. Raman.
19. What was C. V. Raman famous for?
Raman Effect in physics (scattering of light).
20. Name two areas where science is useful today.
Transport and space research.
21. What is an invention?
A new creation that did not exist before.
22. What is a discovery?
Finding something that already exists in nature.
23. Give one example of an invention.
The electric bulb.
24. Give one example of a discovery.
Laws of gravity.
25. How has science changed transport?
Through cars, trains, airplanes, and ships.
26. How has science changed communication?
Through telephones, computers, internet, and satellites.
27. What is the importance of satellites?
They help in weather forecasting, communication, and space research.
28. Name one Indian space scientist.
Dr. A. P. J. Abdul Kalam.
29. What was A. P. J. Abdul Kalam’s contribution?
He contributed to missile technology and space research in India.
30. What is the role of science in industries?
It provides machines, automation, and technology to increase production.
31. Why is science called a “boon”?
Because it has improved human life in many ways.
32. How can science be harmful?
If misused for weapons, pollution, and destruction.
33. Give one example of the misuse of science.
Atomic bombs.
34. Give one example of responsible use of science.
Development of medicines and vaccines.
35. What is meant by “scientific temper”?
Thinking logically, questioning, and reasoning based on evidence.
36. How has science helped in space research?
Through rockets, satellites, and space missions.
37. Name one Indian space mission.
Chandrayaan or Mangalyaan.
38. How has science improved our daily life?
By giving us electricity, transport, communication, and medicines.
39. What should be the aim of science?
To serve humanity and improve life.
40. Write the central idea of this chapter in one line.
Science is an ever-evolving journey that improves human life and must be used responsibly.
LONG QUESTION AND ANSWER
1. Explain why science is called an ever-evolving subject.
Answer: Science is called an ever-evolving subject because it keeps growing and changing with new discoveries and inventions. In ancient times, people discovered fire and invented the wheel, which changed their way of living. Later, inventions such as the telescope, microscope, electricity, and vaccines improved human life. Even today, new technologies like space research and communication systems are developing. This continuous growth makes science ever-evolving.
2. How did the discovery of fire change human life?
Answer: The discovery of fire was a turning point in human life. Early humans used fire for cooking food, which made it easier to digest. Fire also gave warmth during cold weather and protected humans from wild animals. It was later used for making tools and in agriculture. Thus, fire made life safer and more comfortable, leading to human progress.
3. Write about the importance of the invention of the wheel.
Answer: The invention of the wheel was one of the greatest achievements in human history. It made the movement of goods and people easier. With the wheel, carts, chariots, and later vehicles were developed, which improved transport. Today, all vehicles — cars, buses, trains, and airplanes — depend on the principle of the wheel. It helped in trade, travel, and industrial growth, shaping human civilization.
4. How did the invention of the telescope change our knowledge of space?
Answer: The invention of the telescope by Galileo changed our understanding of the universe. Through the telescope, Galileo discovered moons of Jupiter and studied stars and planets in detail. It proved that Earth was not the center of the universe. Telescopes opened the door for modern astronomy, helping scientists study planets, galaxies, and distant stars. Today’s space research depends on advanced telescopes.
5. Explain the role of the microscope in science.
Answer: The microscope, invented by Anton van Leeuwenhoek, allowed humans to see tiny objects not visible to the naked eye. It helped in the discovery of cells, bacteria, and micro-organisms. This led to the growth of biology and medicine. Doctors could identify disease-causing germs and scientists could study living organisms. Thus, the microscope became an important tool for scientific progress.
6. What were Isaac Newton’s contributions to science?
Answer: Isaac Newton made several important contributions to science. He discovered the laws of motion and the law of gravitation. His work explained why objects fall to the ground and how planets move around the sun. Newton also studied light and developed calculus. His discoveries laid the foundation of modern physics and inspired future scientific research.
7. Describe the contributions of Thomas Edison.
Answer: Thomas Edison was a great inventor who gave the world the electric bulb. This invention changed human life completely, bringing light into homes and streets. He also worked on phonographs and motion pictures. Edison’s inventions made life more comfortable and showed how science could improve daily living. He is remembered as one of the greatest inventors of all time.
8. Explain Albert Einstein’s theory of relativity in simple words.
Answer: Albert Einstein developed the theory of relativity, which explained that time and space are not fixed but depend on speed and gravity. This theory changed the way scientists understood the universe. It also helped in the development of modern physics, nuclear energy, and space research. Einstein’s theory is considered one of the greatest scientific contributions.
9. Why are vaccines important for human beings?
Answer: Vaccines are important because they protect humans from dangerous diseases. Edward Jenner discovered the first vaccine for smallpox. Vaccines prepare the body’s immune system to fight against infections. Today, vaccines save millions of lives by preventing diseases like polio, measles, and COVID-19. They are one of the greatest achievements of science in medicine.
10. Explain the role of electricity in modern life.
Answer: Electricity is one of the most important discoveries of science. It powers our homes, industries, schools, and hospitals. Machines, fans, lights, televisions, and computers all run on electricity. In industries, electricity runs machines and increases production. Without electricity, modern life would come to a stop.
11. How has science improved communication?
Answer: Science has completely changed communication. Earlier, people used letters which took many days. Today, telephones, mobiles, and the internet allow instant communication. Social media, video calls, and emails connect people across the world. Satellites make communication faster and more reliable. Science has made the world a global village.
12. How has science improved transport?
Answer: Science has made transport fast and easy. In the past, people traveled on foot or with animals. With science, we now have cars, buses, trains, ships, and airplanes. They save time and connect different parts of the world. Fast transport has improved trade, tourism, and cultural exchange.
13. Explain the role of science in agriculture.
Answer: Science has helped agriculture by providing new machines like tractors, harvesters, and irrigation pumps. High-yield seeds, fertilizers, and pesticides increase production. Weather forecasting helps farmers plan crops. As a result, agriculture has become more productive, feeding millions of people.
14. How has science improved medicine?
Answer: Science has brought great progress in medicine. Vaccines and antibiotics protect people from diseases. Machines like X-ray and MRI help doctors find out illnesses. Surgery has become safer with modern instruments. Science has increased life expectancy and reduced deaths from many diseases.
15. Write a note on C. V. Raman and his contribution.
Answer: C. V. Raman was a famous Indian scientist who discovered the Raman Effect, which explains the scattering of light. For this discovery, he was awarded the Nobel Prize in Physics in 1930. His work brought pride to India and showed the world that Indian scientists could make great contributions.
16. Write a short note on A. P. J. Abdul Kalam’s contribution to science.
Answer: Dr. A. P. J. Abdul Kalam was an Indian scientist who worked in ISRO and DRDO. He played an important role in developing missiles and space technology in India. He is also known as the “Missile Man of India.” Later, he became the President of India and inspired youth to take interest in science.
17. What is the difference between discovery and invention? Give examples.
Answer: Discovery means finding something that already exists in nature. For example, Newton discovered the law of gravity. Invention means creating something new that never existed before. For example, Edison invented the electric bulb. Both discovery and invention help science to progress.
18. How has science helped industries?
Answer: Science has helped industries by providing machines, electricity, and automation. Industries now produce goods faster and in larger quantities. Computers and robots are used in factories. Science has increased production, reduced human effort, and improved the quality of products.
19. How has science helped space research?
Answer: Science has made space research possible. Rockets and satellites are launched to study planets, stars, and the universe. Satellites also help in weather forecasting, communication, and navigation. India’s missions like Chandrayaan and Mangalyaan are examples of progress in space science.
20. Explain the benefits and dangers of science.
Answer: Science has many benefits such as medicines, transport, communication, and technology. It has made life easier and more comfortable. However, misuse of science can be dangerous. Weapons, atomic bombs, and pollution are harmful results of science. Therefore, science should be used only for the welfare of humanity.
21. How has science changed the lifestyle of human beings?
Answer: Science has changed human lifestyle completely. In the past, people lived simple lives, depending on nature. With science, people now have electricity, transport, communication, and advanced medicine. Modern houses, schools, hospitals, and industries are all results of science. It has made life more comfortable, longer, and healthier.
22. Why is Galileo called the father of modern science?
Answer: Galileo is called the father of modern science because he made many discoveries in astronomy and physics. He improved the telescope and observed the moons of Jupiter. He proved that the Earth moves around the sun, which changed the way people understood the universe. His experiments on motion laid the foundation of modern physics.
23. How does science help in disaster management?
Answer: Science helps in disaster management through weather forecasting, satellite images, and communication systems. Scientists can predict cyclones, floods, and earthquakes in advance. This helps in saving lives and reducing damage. Rescue teams use scientific machines and equipment to provide relief during disasters.
24. Explain the importance of satellites in daily life.
Answer: Satellites are important in many ways. They help in communication, television, and internet services. Weather satellites provide information about storms, rainfall, and climate. Navigation satellites guide ships, airplanes, and vehicles. Scientific satellites help in studying space. Satellites make modern life faster and safer.
25. How does science contribute to national development?
Answer: Science contributes to national development by improving agriculture, industries, health, and defense. Scientific inventions increase production and create jobs. Modern medicine keeps people healthy. Science also strengthens defense through advanced weapons and technology. A country that progresses in science becomes strong and self-reliant.
26. How has science helped in education?
Answer: Science has made education more effective. Computers, projectors, and the internet help students learn easily. Online classes and digital libraries make knowledge available to everyone. Scientific inventions like printing presses and calculators have also improved education. Science has made learning faster, interactive, and interesting.
27. Explain the importance of computers in modern life.
Answer: Computers are one of the greatest gifts of science. They are used in schools, offices, banks, hospitals, and industries. Computers store large amounts of information, solve problems quickly, and help in communication. They are also used in designing, research, and entertainment. Today, life is almost impossible without computers.
28. How does science help in protecting the environment?
Answer: Science helps protect the environment through inventions like water purifiers, air filters, and renewable energy sources. Satellites monitor pollution and deforestation. Scientists develop methods for recycling waste and reducing pollution. Clean energy like solar and wind power is also a contribution of science.
29. How did ancient discoveries lay the foundation of modern science?
Answer: Ancient discoveries like fire, the wheel, and basic tools were the starting points of science. Fire helped in cooking and safety. The wheel led to transport. Tools improved agriculture and hunting. These simple discoveries encouraged humans to think and experiment more, leading to modern science.
30. Why must science be used responsibly?
Answer: Science must be used responsibly because it has both benefits and dangers. If used properly, it improves health, education, transport, and industries. If misused, it creates pollution, weapons, and destruction. The atomic bomb is an example of the misuse of science. Therefore, science should always serve humanity and peace.
31. Explain the role of science in space exploration.
Answer: Science has made space exploration possible through rockets, satellites, and space shuttles. Astronauts are able to travel to the moon and beyond. Satellites study planets, stars, and galaxies. Space telescopes give us detailed images of the universe. Indian missions like Chandrayaan and Mangalyaan are examples of how science explores space.
32. How has science changed agriculture?
Answer: Science has improved agriculture through machines, irrigation, fertilizers, and high-yield seeds. Tractors and harvesters save time and effort. Fertilizers and pesticides increase production. Scientific methods of irrigation provide water even in dry areas. These developments help farmers grow more crops and feed large populations.
33. What is the importance of electricity in human life?
Answer: Electricity is one of the most important discoveries of science. It lights our homes, runs machines, and powers industries. Fans, refrigerators, and computers all work on electricity. Hospitals use it for machines like X-rays and ventilators. Without electricity, modern life would stop.
34. How has science improved healthcare?
Answer: Science has improved healthcare by developing medicines, vaccines, and medical equipment. Vaccines protect us from deadly diseases. Machines like X-rays, MRI, and ECG help doctors diagnose illnesses. Surgeries have become safer with modern instruments. Today, life expectancy is longer because of medical science.
35. What is the difference between invention and discovery? Explain with examples.
Answer: An invention is the creation of something new, while a discovery is finding something that already exists in nature. For example, the electric bulb invented by Edison is an invention. Newton’s discovery of gravity is a discovery. Both inventions and discoveries are important for the growth of science.
36. How does science affect industries and economy?
Answer: Science has changed industries by introducing machines, automation, and advanced technology. Machines increase production and reduce labor. Computers and robots make industries faster and more efficient. This creates more goods, more jobs, and improves the economy of a nation.
37. How does science affect communication today?
Answer: Science has revolutionized communication. Telephones, mobile phones, computers, and the internet make communication instant. Video calls and social media connect people across the world. Satellites provide global communication. In the past, messages took days, but today they are sent within seconds.
38. Explain with examples how science can be misused.
Answer: Science can be misused if used for destruction. Nuclear weapons cause mass destruction. Pollution from factories and vehicles harms health. Overuse of machines reduces employment. Technology can also be misused for cybercrimes. These examples show that misuse of science can harm society instead of helping it.
39. How does science influence our daily life?
Answer: Science influences every part of daily life. We wake up with an alarm clock, use electricity, cook food on gas, and travel in cars or buses. Schools, hospitals, and markets all use science. Mobile phones and computers are part of daily communication. From morning to night, science is present everywhere.
40. What is the central idea of the chapter “The Ever-Evolving World of Science”?
Answer: The central idea of the chapter is that science is not fixed but always developing. From ancient discoveries like fire and the wheel to modern inventions like satellites and computers, science has shaped human life. It is a boon when used properly, but harmful if misused. The chapter teaches us to use science responsibly for the progress of humanity.
MULTIPLE CHOICE QUESTIONS (MCQS)
1. The chapter “The Ever-Evolving World of Science” mainly talks about:
a) History of India
b) Progress of science
c) Literature and arts
d) Festivals
Answer: b) Progress of science
2. Which was the first discovery made by early humans?
a) Telescope
b) Fire
c) Computer
d) Telephone
Answer: b) Fire
3. The invention of the wheel helped in:
a) Medicine
b) Transport
c) Space research
d) Communication
Answer: b) Transport
4. Who discovered gravity?
a) Galileo
b) Newton
c) Einstein
d) Edison
Answer: b) Newton
5. The electric bulb was invented by:
a) Edison
b) Newton
c) Galileo
d) Graham Bell
Answer: a) Edison
6. Galileo improved which scientific instrument?
a) Microscope
b) Telescope
c) Telephone
d) Computer
Answer: b) Telescope
7. Who is called the “Father of Modern Science”?
a) Newton
b) Galileo
c) Edison
d) Einstein
Answer: b) Galileo
8. Which invention helps us see very small things?
a) Microscope
b) Telescope
c) Computer
d) Camera
Answer: a) Microscope
9. Which invention helps us see distant objects in space?
a) Microscope
b) Telescope
c) Camera
d) Mobile phone
Answer: b) Telescope
10. Which of these is a discovery, not an invention?
a) Gravity
b) Bulb
c) Telephone
d) Computer
Answer: a) Gravity
11. Who gave the theory of relativity?
a) Newton
b) Galileo
c) Einstein
d) Edison
Answer: c) Einstein
12. Which invention is called the backbone of modern life?
a) Electricity
b) Bulb
c) Telescope
d) Fire
Answer: a) Electricity
13. Which machine is used in almost all fields today?
a) Typewriter
b) Computer
c) Calculator
d) Fan
Answer: b) Computer
14. Satellites are useful for:
a) Cooking
b) Navigation
c) Sports
d) Dancing
Answer: b) Navigation
15. Which Indian mission studied Mars?
a) Chandrayaan
b) Mangalyaan
c) Aryabhata
d) PSLV
Answer: b) Mangalyaan
16. Which of these is NOT a use of science?
a) Medicine
b) Transport
c) Story writing
d) Agriculture
Answer: c) Story writing
17. X-ray machines are used in:
a) Hospitals
b) Agriculture
c) Schools
d) Factories
Answer: a) Hospitals
18. Which invention is used to connect people instantly worldwide?
a) Mobile phone
b) Microscope
c) Telescope
d) Compass
Answer: a) Mobile phone
19. Fire was important for early humans because:
a) It made light and warmth
b) It created pollution
c) It was dangerous
d) It gave electricity
Answer: a) It made light and warmth
20. Vaccines are used for:
a) Entertainment
b) Preventing diseases
c) Food storage
d) Traveling
Answer: b) Preventing diseases
21. Which invention improved agriculture the most?
a) Tractors
b) Computers
c) Aeroplanes
d) Fans
Answer: a) Tractors
22. Science should always be used:
a) For war
b) For destruction
c) For the welfare of society
d) For fun
Answer: c) For the welfare of society
23. Which invention changed industries the most?
a) Typewriter
b) Machines
c) Pen
d) Fire
Answer: b) Machines
24. Overuse of science may lead to:
a) Comfort
b) Pollution
c) Development
d) Growth
Answer: b) Pollution
25. Which of these is NOT an invention of science?
a) Wheel
b) Gravity
c) Computer
d) Bulb
Answer: b) Gravity
26. Who invented the telephone?
a) Newton
b) Edison
c) Alexander Graham Bell
d) Galileo
Answer: c) Alexander Graham Bell
27. Modern education uses:
a) Chalk only
b) Computers and projectors
c) Fire and wheels
d) None of these
Answer: b) Computers and projectors
28. Science in space research is used for:
a) Discovering planets and stars
b) Growing crops
c) Fishing
d) Farming
Answer: a) Discovering planets and stars
29. Which of these is an ancient discovery?
a) Fire
b) Mobile phone
c) Computer
d) Bulb
Answer: a) Fire
30. Modern science began to develop after the work of:
a) Newton and Galileo
b) Edison and Shakespeare
c) Bell and Tagore
d) Aryabhata and Kalidasa
Answer: a) Newton and Galileo
31. Which energy is pollution-free?
a) Coal
b) Petrol
c) Solar
d) Diesel
Answer: c) Solar
32. Which medical discovery increased human life expectancy?
a) Vaccines
b) Tractors
c) Computers
d) Bulbs
Answer: a) Vaccines
33. Which invention changed travel the most?
a) Car
b) Train
c) Aeroplane
d) All of these
Answer: d) All of these
34. Computers can:
a) Store data
b) Calculate quickly
c) Connect through the internet
d) All of these
Answer: d) All of these
35. Which is an example of misuse of science?
a) Satellites
b) Atomic bombs
c) Vaccines
d) Tractors
Answer: b) Atomic bombs
36. Internet is useful for:
a) Learning and communication
b) Cooking
c) Farming
d) Fire making
Answer: a) Learning and communication
37. Why is science called “ever-evolving”?
a) It remains the same
b) It changes with time
c) It stops developing
d) It destroys progress
Answer: b) It changes with time
38. Who discovered that Earth revolves around the Sun?
a) Galileo
b) Newton
c) Edison
d) Einstein
Answer: a) Galileo
39. Which of these is a communication invention?
a) Mobile phone
b) Car
c) Tractor
d) Microscope
Answer: a) Mobile phone
40. What is the main message of the chapter?
a) Science must be used for welfare
b) Science must be stopped
c) Science is dangerous
d) Science is useless
Answer: a) Science must be used for welfare
