CSS General Science & Ability MCQs

This curated collection of MCQs on General Science and Ability for the Central Superior Services (CSS) examination is designed to equip candidates with a thorough understanding of key scientific principles and essential reasoning skills. Covering a wide array of topics, including biology, chemistry, physics, and mathematical reasoning, these questions aim to enhance both knowledge and analytical capabilities critical for success in the CSS exams.

Who Should Practice General Science and Ability MCQs?

CSS aspirants: Ideal for candidates preparing for the CSS examination who seek to improve their performance in the General Science and Ability sections.
Students in related fields: Beneficial for individuals studying disciplines where a strong grasp of scientific concepts and logical reasoning is necessary.
Job seekers: Perfect for those looking to secure positions in government services that require a solid foundation in general science and analytical skills.
Lifelong learners: Suitable for anyone interested in broadening their knowledge of scientific principles and enhancing their problem-solving abilities.

1. The nearest star to Earth is:

A) Proxima Centauri
B) Alpha Centauri
C) Betelgeuse
D) Sirius

View Answer

2. A solar eclipse occurs when:

A) The Earth passes between the Sun and the Moon
B) The Moon passes between the Sun and the Earth
C) The Sun passes between the Earth and the Moon
D) The Earth revolves around the Moon

View Answer

3. The process of water vapor turning into liquid water is called:

A) Evaporation
B) Condensation
C) Sublimation
D) Precipitation

View Answer

4. The Richter scale measures:

A) Temperature
B) Wind speed
C) Earthquake intensity
D) Atmospheric pressure

View Answer

5. The primary source of energy for the Earth is:

A) Wind
B) Solar
C) Geothermal
D) Nuclear

View Answer

6. The basic unit of life is:

A) Tissue
B) Organ
C) Cell
D) Organism

View Answer

7. Antibiotics are used to treat:

A) Viral infections
B) Bacterial infections
C) Fungal infections
D) Parasitic infections

View Answer

8. The atmospheric layer where weather occurs is called:

A) Stratosphere
B) Troposphere
C) Mesosphere
D) Thermosphere

View Answer

9. The greenhouse effect is primarily caused by:

A) Ozone
B) Carbon Dioxide
C) Methane
D) Nitrogen

View Answer

10. Which of the following is a renewable energy source?

A) Coal
B) Natural Gas
C) Solar Energy
D) Oil

View Answer

11. The pH scale measures:

A) Temperature
B) Acidity and alkalinity
C) Pressure
D) Density

View Answer

12. Which organ is responsible for pumping blood in the human body?

A) Brain
B) Lungs
C) Heart
D) Liver

View Answer

13. The process of photosynthesis takes place in:

A) Mitochondria
B) Chloroplasts
C) Nucleus
D) Ribosomes

View Answer

14. The largest planet in our solar system is:

A) Earth
B) Mars
C) Jupiter
D) Saturn

View Answer

15. Deforestation primarily leads to:

A) Increased oxygen production
B) Soil erosion
C) Increased biodiversity
D) Improved air quality

View Answer

16. Which gas is most abundant in the Earth’s atmosphere?

A) Oxygen
B) Carbon Dioxide
C) Nitrogen
D) Argon

View Answer

17. What type of bond involves the sharing of electron pairs?

A) Ionic
B) Covalent
C) Metallic
D) Hydrogen

View Answer

18. The primary role of mitochondria in a cell is:

A) Photosynthesis
B) Energy production
C) Protein synthesis
D) DNA replication

View Answer

19. Which of the following is NOT a greenhouse gas?

A) Carbon Dioxide
B) Methane
C) Nitrous Oxide
D) Oxygen

View Answer

20. The water cycle includes all of the following processes EXCEPT:

A) Evaporation
B) Condensation
C) Precipitation
D) Filtration

View Answer

21. Which vitamin is primarily obtained from sunlight?

A) Vitamin A
B) Vitamin B
C) Vitamin C
D) Vitamin D

View Answer

22. The Earth revolves around the Sun in approximately:

A) 24 hours
B) 365 days
C) 30 days
D) 12 months

View Answer

23. A substance that speeds up a chemical reaction is called:

A) Catalyst
B) Inhibitor
C) Reactant
D) Product

View Answer

24. Which part of the brain controls balance and coordination?

A) Cerebrum
B) Cerebellum
C) Brainstem
D) Thalamus

View Answer

25. What type of rock is formed by cooling and solidification of magma?

A) Sedimentary
B) Metamorphic
C) Igneous
D) Fossil

View Answer

26. The process of producing biofuel from organic materials is called:

A) Fermentation
B) Photosynthesis
C) Gasification
D) Biomass conversion

View Answer

27. The study of heredity and variation is known as:

A) Evolution
B) Genetics
C) Ecology
D) Microbiology

View Answer

28. The chemical symbol for sodium is:

A) S
B) Na
C) So
D) Sd

View Answer

29. The greenhouse effect is primarily caused by:

A) Increased levels of oxygen
B) Increased levels of nitrogen
C) Increased levels of greenhouse gases
D) Decreased levels of carbon dioxide

View Answer

30. The main purpose of a food preservative is to:

A) Enhance flavor
B) Extend shelf life
C) Improve texture
D) Increase nutritional value

View Answer

31. The Earth’s lithosphere is composed mainly of:

A) Water
B) Air
C) Rocks and minerals
D) Living organisms

View Answer

32. What type of lens is used to correct nearsightedness?

A) Convex
B) Concave
C) Biconcave
D) Cylindrical

View Answer

33. The function of red blood cells is to:

A) Fight infection
B) Carry oxygen
C) Clot blood
D) Regulate temperature

View Answer

34. What is the primary cause of ocean acidification?

A) Excessive fishing
B) Deforestation
C) Increased carbon dioxide absorption
D) Overfishing

View Answer

35. Which disease is caused by a virus?

A) Tuberculosis
B) Malaria
C) Polio
D) Cholera

View Answer

36. Which gas is produced during photosynthesis?

A) Carbon Dioxide
B) Oxygen
C) Nitrogen
D) Methane

View Answer

37. The unit of force is:

A) Joule
B) Watt
C) Newton
D) Pascal

View Answer

38. The chemical formula for table salt is:

A) NaOH
B) NaCl
C) KCl
D) CaCO3

View Answer

39. Which of the following is a biotic factor in an ecosystem?

A) Water
B) Soil
C) Plants
D) Temperature

View Answer

40. The measure of how much mass is contained in a given volume is known as:

A) Weight
B) Density
C) Volume
D) Mass

View Answer

41. The boiling point of water at sea level is:

A) 50°C
B) 100°C
C) 150°C
D) 200°C

View Answer

42. The organ responsible for detoxifying chemicals in the body is:

A) Kidney
B) Liver
C) Pancreas
D) Spleen

View Answer

43. The primary component of the Earth’s atmosphere is:

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Argon

View Answer

44. The unit of power is:

A) Joule
B) Watt
C) Volt
D) Ampere

View Answer

45. Which nutrient is essential for building and repairing tissues?

A) Carbohydrates
B) Fats
C) Proteins
D) Vitamins

View Answer

46. The process by which plants absorb water from the soil is called:

A) Evaporation
B) Absorption
C) Transpiration
D) Photosynthesis

View Answer

47. What is the main function of chlorophyll in plants?

A) Absorb sunlight
B) Store nutrients
C) Release oxygen
D) Produce carbon dioxide

View Answer

48. The primary source of energy for most living organisms is:

A) Water
B) Sunlight
C) Wind
D) Geothermal

View Answer

49. Which of the following diseases is caused by a parasite?

A) Hepatitis
B) Malaria
C) Influenza
D) Tuberculosis

View Answer

50. The main function of the kidneys is to:

A) Pump blood
B) Filter waste from blood
C) Produce hormones
D) Store nutrients

View Answer

51. Which type of pollution affects the quality of air?

A) Water Pollution
B) Soil Pollution
C) Noise Pollution
D) Atmospheric Pollution

View Answer

52. The Earth’s crust is made up of:

A) Gases
B) Water
C) Solids
D) Liquids

View Answer

53. The process of converting a solid directly into a gas is called:

A) Evaporation
B) Sublimation
C) Condensation
D) Deposition

View Answer

54. Which vitamin is essential for vision?

A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin E

View Answer

55. The study of ecosystems and the interactions between organisms and their environment is called:

A) Genetics
B) Ecology
C) Microbiology
D) Botany

View Answer

56. Which of the following elements is essential for plant growth?

A) Gold
B) Nitrogen
C) Silver
D) Mercury

View Answer

57. The temperature at which a liquid boils is called:

A) Freezing point
B) Melting point
C) Boiling point
D) Condensation point

View Answer

58. The smallest unit of an element that retains its properties is:

A) Molecule
B) Atom
C) Compound
D) Ion

View Answer

59. Which of the following is a primary pollutant?

A) Ozone
B) Carbon Dioxide
C) Sulfur Dioxide
D) Nitrogen Oxides

View Answer

60. Which gas is commonly known as laughing gas?

A) Nitrous Oxide
B) Carbon Dioxide
C) Methane
D) Oxygen

View Answer

61. The main function of enzymes in biological processes is to:

A) Slow down reactions
B) Speed up reactions
C) Provide energy
D) Store nutrients

View Answer

62. The unit of measurement for electric current is:

A) Volt
B) Ohm
C) Ampere
D) Watt

View Answer

63. The primary component of the human skeleton is:

A) Calcium
B) Phosphorus
C) Collagen
D) Keratin

View Answer

64. The main purpose of a food additive is to:

A) Increase calories
B) Preserve freshness
C) Reduce flavor
D) Lower nutritional value

View Answer

65. Which of the following is NOT a macronutrient?

A) Carbohydrates
B) Proteins
C) Vitamins
D) Fats

View Answer

66. The energy stored in the bonds of chemical compounds is known as:

A) Kinetic energy
B) Thermal energy
C) Potential energy
D) Mechanical energy

View Answer

67. The most abundant gas in the Earth’s atmosphere is:

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Helium

View Answer

68. Which of the following organs is primarily responsible for digestion?

A) Lungs
B) Heart
C) Stomach
D) Brain

View Answer

69. The movement of water from the Earth’s surface to the atmosphere and back is known as:

A) Water Cycle
B) Carbon Cycle
C) Nitrogen Cycle
D) Oxygen Cycle

View Answer

70. The study of fungi is known as:

A) Botany
B) Zoology
C) Mycology
D) Ecology

View Answer

71. The chemical process that occurs in plants to convert sunlight into energy is called:

A) Respiration
B) Fermentation
C) Photosynthesis
D) Digestion

View Answer

72. The primary purpose of the ozone layer is to:

A) Absorb carbon dioxide
B) Protect against UV radiation
C) Provide oxygen
D) Store heat

View Answer

73. The Earth’s outer core is primarily made of:

A) Solid rock
B) Liquid iron and nickel
C) Gases
D) Ice

View Answer

74. Which organ is responsible for the detoxification of drugs and poisons?

A) Kidney
B) Liver
C) Pancreas
D) Spleen

View Answer

75. Which nutrient is important for healthy skin and vision?

A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin E

View Answer

76. The organ that regulates body temperature is:

A) Brain
B) Heart
C) Skin
D) Liver

View Answer

77. The primary function of red blood cells is to:

A) Carry oxygen
B) Fight infections
C) Clot blood
D) Regulate body temperature

View Answer

78. The term used to describe a population’s maximum sustainable size is:

A) Carrying capacity
B) Population density
C) Exponential growth
D) Logistic growth

View Answer

79. The type of energy stored in food is:

A) Kinetic energy
B) Potential energy
C) Thermal energy
D) Chemical energy

View Answer

80. The process of breaking down glucose to produce energy is called:

A) Photosynthesis
B) Respiration
C) Fermentation
D) Digestion

View Answer

81. The chemical formula for water is:

A) CO2
B) H2O
C) O2
D) CH4

View Answer

82. The primary cause of acid rain is:

A) Increased oxygen levels
B) Increased carbon emissions
C) Increased sulfur dioxide emissions
D) Increased nitrogen levels

View Answer

83. Which of the following is a non-renewable energy source?

A) Wind
B) Solar
C) Coal
D) Hydro

View Answer

84. The most common element in the universe is:

A) Oxygen
B) Hydrogen
C) Helium
D) Carbon

View Answer

85. Which type of bond involves the transfer of electrons?

A) Covalent
B) Ionic
C) Metallic
D) Hydrogen

View Answer

86. The primary organ involved in the immune response is:

A) Brain
B) Lungs
C) Heart
D) Spleen

View Answer

87. The chemical symbol for potassium is:

A) P
B) K
C) Po
D) Pt

View Answer

88. Which of the following is NOT a characteristic of living things?

A) Growth
B) Reproduction
C) Inability to respond to stimuli
D) Metabolism

View Answer

89. The process of converting liquid to gas is known as:

A) Condensation
B) Evaporation
C) Freezing
D) Melting

View Answer

90. The main purpose of photosynthesis is to:

A) Produce carbon dioxide
B) Produce glucose
C) Absorb oxygen
D) Release heat

View Answer

91. The scientific study of behavior and mental processes is known as:

A) Biology
B) Sociology
C) Psychology
D) Anthropology

View Answer

92. The primary structure that separates the inside of a cell from the outside environment is called:

A) Cell wall
B) Nucleus
C) Cell membrane
D) Cytoplasm

View Answer

93. Which nutrient is primarily responsible for providing energy?

A) Proteins
B) Carbohydrates
C) Vitamins
D) Minerals

View Answer

94. The Earth’s atmosphere is composed of approximately what percentage of nitrogen?

A) 21%
B) 78%
C) 50%
D) 5%

View Answer

95. The process by which bacteria convert nitrogen gas into ammonia is called:

A) Nitrogen fixation
B) Nitrification
C) Denitrification
D) Ammonification

View Answer

96. The primary role of the digestive system is to:

A) Pump blood
B) Remove waste
C) Break down food
D) Store nutrients

View Answer

97. The most common type of rock on the Earth’s surface is:

A) Igneous
B) Sedimentary
C) Metamorphic
D) Magma

View Answer

98. The formula for calculating density is:

A) Mass × Volume
B) Mass / Volume
C) Volume / Mass
D) Mass + Volume

View Answer

99. The primary source of carbon dioxide in the atmosphere is:

A) Photosynthesis
B) Respiration
C) Combustion of fossil fuels
D) Volcanic eruptions

View Answer

100. The process of changing from a gas to a liquid is called:

A) Condensation
B) Evaporation
C) Sublimation
D) Freezing

View Answer