Science Quiz Questions and Answers - Science General Knowledge - GK Questions with Answers

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Science Quiz Questions and Answers - Science General Knowledge

1. Lucifer is another name for the planet ___.

1. Jupiter
2. Mars
3. Venus
4. Saturn

Answer: C) Venus

Explanation: Lucifer is another name for the planet Venus. The word Lucifer comes from Latin, meaning "light-bringer" or "morning star". Venus is often visible in the sky either just before sunrise (called the "Morning Star") or just after sunset (called the "Evening Star"). The planet Venus is the third brightest natural object in the sky after the Sun and the Moon. Venus is called Earth’s twin because of its similar size, mass, and composition, but it has an extremely dense atmosphere mainly composed of carbon dioxide, leading to a runaway greenhouse effect and very high surface temperatures. The surface temperature of Venus can reach up to 465°C, making it the hottest planet in our solar system.

2. Which of the following dwarf planets lies in the main asteroid belt?

1. Eris
2. Makemake
3. Haumea
4. Ceres

Answer: D) Ceres

Explanation: Ceres is the only dwarf planet located in the main asteroid belt between Mars and Jupiter. Ceres is the largest object in the asteroid belt, with a diameter of about 940 km. Unlike most asteroids, Ceres is spherical in shape due to its self-gravity, which is one reason it qualifies as a dwarf planet. The surface of Ceres contains a mixture of water ice and rock. Scientists believe that Ceres may have a subsurface ocean, making it important for the study of potential extraterrestrial life. Other well-known dwarf planets like Eris, Makemake, and Haumea are located in the Kuiper Belt, which lies beyond Neptune, not in the main asteroid belt.

3. Earth's Core is mainly made up of

1. Nickel and Copper
2. Nickel and Iron
3. Nickel and Alumina
4. Nickel and Magnesium

Answer: B) Nickel and Iron

Explanation: The Earth’s core is mainly composed of nickel and iron, which is why it is often referred to as the Nife core. The Earth’s internal structure has three main layers: the crust, the mantle, and the core. The core itself has two parts: Outer core: It is in a liquid state and mainly consists of molten iron and nickel. The movement of this molten metal generates the Earth’s magnetic field through the geodynamo effect. Inner core: It is in a solid state despite the extremely high temperature, because of the enormous pressure. It is also composed primarily of iron and nickel. Elements like copper, alumina (Al₂O₃), and magnesium are found in the Earth’s crust and mantle but not in significant amounts in the core. The core plays a vital role in protecting Earth by generating a magnetic field, which shields the planet from harmful solar wind and cosmic radiation.

4. Which layer of atmosphere helps in radio transmission?

1. Exosphere
2. Thermosphere
3. Mesosphere
4. Stratosphere

Answer: B) Thermosphere

Explanation: The Thermosphere is the atmospheric layer that helps in radio transmission because it contains the ionosphere, which reflects and refracts radio waves back to the Earth’s surface. The ionosphere is not a separate layer but a region within the thermosphere (and partly in the mesosphere and exosphere) where solar radiation ionizes atmospheric gases, producing free electrons and ions. These charged particles make the ionosphere capable of reflecting medium-frequency (MF) and high-frequency (HF) radio waves, allowing long-distance communication without satellites. The thermosphere extends from about 80 km to 700 km above the Earth’s surface. The thermosphere also contains the auroras (Northern and Southern Lights), caused by charged solar particles interacting with Earth’s magnetic field and atmosphere.

5. The Ozone layer is found in the __ layer.

1. Stratosphere
2. Mesosphere
3. Thermosphere
4. Exosphere

Answer: A) Stratosphere

Explanation: The Ozone layer is located in the Stratosphere, roughly between 15 km and 35 km above the Earth’s surface. The Stratosphere is the second layer of the atmosphere, lying above the Troposphere and below the Mesosphere. The ozone layer contains a high concentration of ozone gas (O₃), which plays a critical role in absorbing ultraviolet (UV) radiation from the Sun. This absorption of UV radiation protects life on Earth by preventing harmful UV-B and UV-C rays from reaching the surface, which can cause skin cancer, cataracts, and genetic damage in humans, and harm crops and ecosystems. The ozone hole refers to the thinning of the ozone layer, especially over Antarctica, caused by chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS). Unlike the Troposphere, where weather occurs, the Stratosphere is stable and has less turbulence, which is why commercial aircraft often fly at this height.

6. Blue green algae are included in the group?

1. Eubacteria
2. Cyanobacteria
3. Protozoa
4. Fungi

Answer: B) Cyanobacteria

Explanation: Blue-green algae are not true algae but belong to the group of Cyanobacteria. They are prokaryotic organisms that perform photosynthesis like plants, but they lack a true nucleus and membrane-bound organelles. Cyanobacteria contain the pigment chlorophyll-a, which helps in photosynthesis, giving them their blue-green color. They are considered some of the earliest life forms on Earth and played a crucial role in producing oxygen in the atmosphere billions of years ago. They are found in freshwater, marine, and terrestrial habitats and can survive in extreme conditions. Some forms of cyanobacteria, like Anabaena and Nostoc, also fix atmospheric nitrogen, making them important for soil fertility.

7. Why does fish die in summer season as compared to winter season? It is because of

1. Shortage of food
2. Concentration of toxins
3. Depletion of oxygen
4. Spread of diseases

Answer: C) Depletion of oxygen

Explanation: Fish need dissolved oxygen in water for respiration. The amount of oxygen that water can hold depends on temperature. During the summer season, water temperature rises, and the solubility of oxygen decreases. This results in a significant depletion of oxygen in ponds, lakes, and rivers. At the same time, higher temperatures increase the respiration rate of aquatic organisms and promote the growth of microorganisms and algae, which consume even more oxygen. As a result, fish often die due to lack of sufficient dissolved oxygen in the water. In contrast, during winter, water is cooler, which allows more oxygen to dissolve, and respiration rates are slower, so fish survival is higher.

8. The pollen grains of flowers pollinated by insects are:

1. Rough and sticky
2. Smooth and dry
3. Rough and dry
4. Large and showy

Answer: A) Rough and sticky

Explanation: Flowers that are pollinated by insects (called entomophilous flowers) need to ensure that pollen grains are carried effectively from one flower to another by insects such as bees, butterflies, beetles, and flies. For this purpose, their pollen grains are usually rough, spiny, and sticky. The sticky surface helps the pollen adhere to the bodies of insects when they visit flowers in search of nectar. The rough texture prevents the pollen from being easily dislodged. In contrast, flowers pollinated by wind (anemophilous flowers) produce smooth, light, and dry pollen that can be easily carried by air currents.

9. The mains pollutant responsible for Bhopal Gas Tragedy is

1. Bromine
2. Chlorofluorocarbon
3. Chlorine
4. Methyl Isocyanate

Answer: D) Methyl Isocyanate

Explanation: The Bhopal Gas Tragedy occurred on the night of 2–3 December 1984 at the Union Carbide pesticide plant in Bhopal, Madhya Pradesh. It is considered the world’s worst industrial disaster. The tragedy was caused by the leakage of a toxic chemical called Methyl Isocyanate (MIC), which is used in the production of pesticides (such as carbaryl/sevin). When water accidentally entered a storage tank containing MIC, a violent chemical reaction occurred, releasing deadly MIC gas into the atmosphere. The gas spread rapidly through nearby densely populated areas, causing severe respiratory problems, eye irritation, blindness, organ damage, and death. Thousands of people died immediately, and lakhs of survivors suffered long-term health effects, including birth defects, cancer, and lung diseases.

10. What is the role of Pneumatophores?

1. Protect plant from animals
2. Get oxygen for respiration
3. Supports plant in standing upright
4. Helps plant for pollination

Answer: B) Get oxygen for respiration

Explanation: Pneumatophores are special types of aerial roots found in plants that grow in swampy or marshy areas (such as mangroves). These soils are usually waterlogged and deficient in oxygen. To overcome this problem, some roots grow vertically upwards from the soil or water surface. These roots are called pneumatophores (breathing roots). Their main function is to absorb oxygen directly from the atmosphere through small pores called lenticels present on their surface. Thus, pneumatophores help the plant in respiration when the underground root system is deprived of oxygen.

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11. Which layer of the Sun is visible during a total solar eclipse?

1. Core
2. Radiative zone
3. Photosphere
4. Corona

Answer: D) Corona

12. What is the primary source of energy for photosynthesis?

1. Nitrogen
2. Oxygen
3. Sunlight
4. Carbon dioxide

Answer: C) Sunlight

13. What is the term for the process by which a habitat becomes progressively drier and more desert-like?

1. Eutrophication
2. Desertification
3. Acidification
4. Salinization

Answer: B) Desertification

14. Which greenhouse gas is primarily responsible for global warming?

1. Carbon dioxide
2. Methane
3. Nitrous oxide
4. Ozone

Answer: A) Carbon dioxide

15. What is the primary cause of the “hole in the ozone layer”?

1. Pesticides
2. Chlorofluorocarbons (CFCs)
3. Volcanic activity
4. Acid rain

Answer: B) Chlorofluorocarbons (CFCs)

16. What is the term for the process by which a body of water becomes enriched in nutrients, leading to excessive plant growth?

1. Oligotrophication
2. Hypoxia
3. Eutrophication
4. Desalination

Answer: C) Eutrophication

17. Which of the following is a renewable resource?

1. Coal
2. Petroleum
3. Natural gas
4. Wind energy

Answer: D) Wind energy

18. What is the primary cause of soil erosion?

1. Deforestation
2. Overgrazing
3. Urbanization
4. Acid rain

Answer: A) Deforestation

19. What is the term for the process of converting waste materials into reusable materials?

1. Incineration
2. Recycling
3. Landfilling
4. Composting

Answer: B) Recycling

20. What is the primary role of decomposers in an ecosystem?

1. Produce oxygen
2. Fix nitrogen
3. Conduct photosynthesis
4. Break down dead organic matter

Answer: D) Break down dead organic matter

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21. The main function of the human small intestine is:

1. Water absorption
2. Digestion of proteins
3. Absorption of nutrients
4. Absorption of fats only

Answer: C) Absorption of nutrients

22. Which part of the brain maintains posture and balance of the body?

1. Cerebrum
2. Cerebellum
3. Medulla
4. Pons

Answer: B) Cerebellum

23. The hormone responsible for the regulation of sugar level in the blood is:

1. Adrenaline
2. Thyroxine
3. Insulin
4. Estrogen

Answer: C) Insulin

24. In which of the following organisms does binary fission occur?

1. Yeast
2. Hydra
3. Plasmodium
4. Amoeba

Answer: D) Amoeba

25. Which organ in human females produces eggs?

1. Ovary
2. Uterus
3. Oviduct
4. Cervix

Answer: A) Ovary

26. Which of the following is a non-biodegradable waste?

1. Fruit peels
2. Paper
3. Plastic
4. Cotton cloth

Answer: C) Plastic

27. The human eye forms the image of an object at its:

1. Iris
2. Pupil
3. Cornea
4. Retina

Answer: D) Retina

28. Which phenomenon is responsible for the twinkling of stars?

1. Reflection
2. Refraction
3. Dispersion
4. Scattering

Answer: B) Refraction

29. The sky appears blue because of:

1. Dispersion of light
2. Total internal reflection
3. Scattering of light
4. Refraction of light

Answer: C) Scattering of light

30. The SI unit of electric current is:

1. Ampere
2. Volt
3. Ohm
4. Coulomb

Answer: A) Ampere

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31. Newton’s First Law is also called the law of:

1. Force
2. Inertia
3. Action
4. Acceleration

Answer: B) Inertia

32. Which was the first genetically modified (GM) plant approved for commercial cultivation in India?

1. Golden Rice
2. Bt Brinjal
3. Bt Cotton
4. GM Mustard

Answer: C) Bt Cotton

33. Who proposed the planetary model of an atom?

1. Rutherford
2. J.J. Thomson
3. Niels Bohr
4. Dalton

Answer: A) Rutherford

34. The cell organelle responsible for protein synthesis is:

1. Mitochondria
2. Ribosomes
3. Golgi apparatus
4. Lysosomes

Answer: B) Ribosomes

35. Which of the following is a disaccharide?

1. Glucose
2. Fructose
3. Maltose
4. Galactose

Answer: C) Maltose

36. Water is absorbed by roots through the process of:

1. Active transport
2. Transpiration
3. Diffusion
4. Osmosis

Answer: D) Osmosis

37. Which of the following is not a fundamental force in nature?

1. Gravitational force
2. Electrostatic force
3. Frictional force
4. Strong nuclear force

Answer: C) Frictional force

38. Which of the following groups contains prokaryotic organisms?

1. Monera
2. Protista
3. Fungi
4. Plantae

Answer: A) Monera

39. Which of the following organisms is unicellular and eukaryotic?

1. Bacteria
2. Amoeba
3. Virus
4. Nostoc

Answer: B) Amoeba

40. Lichens are a symbiotic association of:

1. Algae and protozoa
2. Fungi and bacteria
3. Fungi and algae
4. Fungi and moss

Answer: C) Fungi and algae

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41. Which of the following is not a characteristic of particles of matter?

1. They have spaces between them
2. They are stationary
3. They attract each other
4. They are constantly moving

Answer: B) They are stationary

42. A mixture of salt and water is an example of:

1. Heterogeneous mixture
2. Compound
3. Element
4. Homogeneous mixture

Answer: D) Homogeneous mixture

43. The conversion of a solid directly into gas is called:

1. Condensation
2. Evaporation
3. Sublimation
4. Freezing

Answer: C) Sublimation

44. Which method is used to separate cream from milk?

1. Centrifugation
2. Filtration
3. Evaporation
4. Sublimation

Answer: A) Centrifugation

45. The nucleus of an atom contains:

1. Protons only
2. Electrons only
3. Protons and Neutrons
4. Electrons and Neutrons

Answer: C) Protons and Neutrons

46. The cell organelle responsible for respiration is:

1. Ribosome
2. Mitochondria
3. Golgi body
4. Lysosome

Answer: B) Mitochondria

47. Which tissue helps in the movement of our body?

1. Connective
2. Nervous
3. Epithelial
4. Muscular

Answer: D) Muscular

48. Which kingdom includes multicellular, autotrophic organisms?

1. Fungi
2. Animalia
3. Plantae
4. Monera

Answer: C) Plantae

49. Sound cannot travel through:

1. Solids
2. Liquids
3. Gases
4. Vacuum

Answer: D) Vacuum

50. Malaria is caused by:

1. Protozoa
2. Bacteria
3. Virus
4. Fungi

Answer: A) Protozoa

51. What is the main cause of lightning during thunderstorms?

1. High wind speeds
2. Friction between water droplets and ice particles in clouds
3. Magnetic fields of the Earth
4. Rotation of the Earth

Answer: B) Friction between water droplets and ice particles in clouds