Here are 50 Science MCQs with answers, suitable for school-level practice.
Science MCQ – 50 Questions
What is the basic unit of life?
A) Tissue
B) Cell
C) Organ
D) Atom
Answer: B) Cell
Which planet is known as the Red Planet?
A) Earth
B) Venus
C) Mars
D) Jupiter
Answer: C) Mars
What gas do plants absorb during photosynthesis?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Answer: C) Carbon dioxide
Which organ pumps blood throughout the human body?
A) Brain
B) Heart
C) Lungs
D) Kidney
Answer: B) Heart
What is the boiling point of water at normal atmospheric pressure?
A) 50°C
B) 75°C
C) 100°C
D) 150°C
Answer: C) 100°C
Which is the largest planet in our solar system?
A) Earth
B) Saturn
C) Jupiter
D) Neptune
Answer: C) Jupiter
Which vitamin is mainly produced in our skin in sunlight?
A) Vitamin A
B) Vitamin B
C) Vitamin C
D) Vitamin D
Answer: D) Vitamin D
What force pulls objects toward Earth?
A) Friction
B) Gravity
C) Magnetism
D) Electricity
Answer: B) Gravity
Which metal is liquid at room temperature?
A) Iron
B) Copper
C) Mercury
D) Aluminium
Answer: C) Mercury
Which part of a plant absorbs water from the soil?
A) Leaf
B) Stem
C) Flower
D) Root
Answer: D) Root
How many bones are there in an adult human body?
A) 106
B) 206
C) 306
D) 406
Answer: B) 206
Which gas is essential for human respiration?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen
Answer: A) Oxygen
What is H₂O commonly known as?
A) Salt
B) Water
C) Oxygen
D) Hydrogen
Answer: B) Water
Which is the nearest star to Earth?
A) Sirius
B) Polaris
C) Sun
D) Alpha Centauri
Answer: C) Sun
Which organ is mainly responsible for filtering waste from the blood?
A) Heart
B) Kidney
C) Stomach
D) Lungs
Answer: B) Kidney
What is the SI unit of force?
A) Joule
B) Watt
C) Newton
D) Pascal
Answer: C) Newton
Which part of the cell contains genetic material?
A) Cell wall
B) Nucleus
C) Cytoplasm
D) Vacuole
Answer: B) Nucleus
Which disease is caused by a deficiency of vitamin C?
A) Rickets
B) Scurvy
C) Beriberi
D) Night blindness
Answer: B) Scurvy
Which animal is known as the fastest land animal?
A) Lion
B) Horse
C) Cheetah
D) Tiger
Answer: C) Cheetah
What is the freezing point of water?
A) 0°C
B) 10°C
C) 50°C
D) 100°C
Answer: A) 0°C
Which gas makes up the largest percentage of Earth’s atmosphere?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Answer: B) Nitrogen
Which instrument is used to measure temperature?
A) Barometer
B) Thermometer
C) Ammeter
D) Hygrometer
Answer: B) Thermometer
Which blood cells help fight infections?
A) Red blood cells
B) White blood cells
C) Platelets
D) Plasma
Answer: B) White blood cells
Which is the hardest natural substance?
A) Iron
B) Gold
C) Diamond
D) Silver
Answer: C) Diamond
What is the main source of energy for Earth?
A) Moon
B) Sun
C) Wind
D) Water
Answer: B) Sun
Which planet has prominent rings?
A) Mercury
B) Venus
C) Saturn
D) Mars
Answer: C) Saturn
Which organ helps us breathe?
A) Liver
B) Lungs
C) Kidney
D) Stomach
Answer: B) Lungs
What is the chemical symbol for gold?
A) Go
B) Gd
C) Au
D) Ag
Answer: C) Au
Which simple machine is commonly used to draw water from a well?
A) Pulley
B) Lever
C) Screw
D) Wedge
Answer: A) Pulley
Which part of the human body controls thinking and memory?
A) Heart
B) Brain
C) Liver
D) Kidney
Answer: B) Brain
What is the process by which plants make their food?
A) Respiration
B) Digestion
C) Photosynthesis
D) Excretion
Answer: C) Photosynthesis
Which acid is present in lemon?
A) Hydrochloric acid
B) Citric acid
C) Sulfuric acid
D) Nitric acid
Answer: B) Citric acid
Which form of energy is stored in food?
A) Chemical energy
B) Sound energy
C) Light energy
D) Nuclear energy
Answer: A) Chemical energy
Which device converts electrical energy into light energy?
A) Bulb
B) Motor
C) Generator
D) Battery
Answer: A) Bulb
Which planet is closest to the Sun?
A) Earth
B) Mercury
C) Venus
D) Mars
Answer: B) Mercury
Which substance is necessary for burning?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Helium
Answer: A) Oxygen
Which organ produces bile?
A) Stomach
B) Liver
C) Kidney
D) Pancreas
Answer: B) Liver
What is the SI unit of electric current?
A) Volt
B) Watt
C) Ampere
D) Ohm
Answer: C) Ampere
Which natural satellite revolves around Earth?
A) Sun
B) Moon
C) Mars
D) Venus
Answer: B) Moon
Which nutrient is mainly responsible for body growth and repair?
A) Protein
B) Fat
C) Water
D) Minerals
Answer: A) Protein
Which material is a good conductor of electricity?
A) Rubber
B) Plastic
C) Copper
D) Wood
Answer: C) Copper
Which part of the eye controls the amount of light entering it?
A) Retina
B) Iris
C) Lens
D) Cornea
Answer: B) Iris
What is the center of an atom called?
A) Electron
B) Nucleus
C) Proton
D) Shell
Answer: B) Nucleus
Which gas is released by plants during photosynthesis?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Answer: A) Oxygen
Which instrument is used to measure atmospheric pressure?
A) Thermometer
B) Barometer
C) Ammeter
D) Speedometer
Answer: B) Barometer
Which part of the plant carries water from roots to leaves?
A) Phloem
B) Xylem
C) Flower
D) Fruit
Answer: B) Xylem
Which type of energy is produced by a moving object?
A) Kinetic energy
B) Chemical energy
C) Nuclear energy
D) Potential energy
Answer: A) Kinetic energy
Which disease is caused by a lack of vitamin D?
A) Scurvy
B) Rickets
C) Anemia
D) Beriberi
Answer: B) Rickets
Which is the largest organ of the human body?
A) Heart
B) Liver
C) Skin
D) Brain
Answer: C) Skin
Which process changes liquid water into water vapour?
A) Freezing
B) Melting
C) Evaporation
D) Condensation
Answer: C) Evaporation
