Q.1 Which gas is most abundant in the Earth's atmosphere?
Oxygen
Nitrogen
Carbon Dioxide
Hydrogen
Explanation - Nitrogen makes up about 78% of the Earth's atmosphere, making it the most abundant gas.
Correct answer is: Nitrogen
Q.2 Which part of the human brain controls balance and coordination?
Cerebrum
Cerebellum
Medulla
Hypothalamus
Explanation - The cerebellum is responsible for coordinating voluntary movements, balance, and posture.
Correct answer is: Cerebellum
Q.3 What is the chemical symbol for gold?
Au
Ag
Gd
Ga
Explanation - Gold has the chemical symbol 'Au', derived from its Latin name 'Aurum'.
Correct answer is: Au
Q.4 Which organ in the human body produces insulin?
Liver
Pancreas
Kidney
Spleen
Explanation - The pancreas produces insulin, a hormone that regulates blood sugar levels.
Correct answer is: Pancreas
Q.5 What is the boiling point of water at sea level?
90°C
100°C
110°C
120°C
Explanation - At standard atmospheric pressure (sea level), water boils at 100°C.
Correct answer is: 100°C
Q.6 Which vitamin is mainly obtained from sunlight?
Vitamin A
Vitamin B12
Vitamin C
Vitamin D
Explanation - Vitamin D is synthesized in the skin when exposed to sunlight.
Correct answer is: Vitamin D
Q.7 Which planet is known as the 'Red Planet'?
Venus
Mars
Jupiter
Saturn
Explanation - Mars is called the Red Planet due to its reddish appearance caused by iron oxide on its surface.
Correct answer is: Mars
Q.8 What is the primary function of red blood cells?
Fight infections
Carry oxygen
Clot blood
Produce hormones
Explanation - Red blood cells contain hemoglobin which transports oxygen from the lungs to the body's tissues.
Correct answer is: Carry oxygen
Q.9 Which element is a noble gas?
Nitrogen
Oxygen
Neon
Hydrogen
Explanation - Neon is a noble gas, chemically inert and found in group 18 of the periodic table.
Correct answer is: Neon
Q.10 Which part of the plant conducts photosynthesis?
Root
Stem
Leaf
Flower
Explanation - Leaves contain chlorophyll, which captures sunlight and conducts photosynthesis.
Correct answer is: Leaf
Q.11 Which gas do plants absorb from the atmosphere for photosynthesis?
Oxygen
Carbon Dioxide
Nitrogen
Hydrogen
Explanation - Plants absorb carbon dioxide from the air and use it in photosynthesis to produce glucose and oxygen.
Correct answer is: Carbon Dioxide
Q.12 Which blood type is known as the universal donor?
O+
O-
AB+
AB-
Explanation - O-negative blood can be transfused to people of any blood type, making it the universal donor.
Correct answer is: O-
Q.13 Which is the heaviest naturally occurring element?
Uranium
Osmium
Lead
Platinum
Explanation - Uranium (atomic number 92) is the heaviest naturally occurring element found in nature.
Correct answer is: Uranium
Q.14 Which organ filters blood to remove waste products in humans?
Heart
Kidney
Liver
Lungs
Explanation - Kidneys filter waste products and excess water from the blood to form urine.
Correct answer is: Kidney
Q.15 Which acid is found in the human stomach?
Hydrochloric Acid
Sulfuric Acid
Nitric Acid
Acetic Acid
Explanation - Hydrochloric acid in the stomach helps digest food and kill harmful bacteria.
Correct answer is: Hydrochloric Acid
Q.16 Which part of the eye controls the amount of light entering it?
Cornea
Iris
Lens
Retina
Explanation - The iris adjusts the size of the pupil to regulate the amount of light entering the eye.
Correct answer is: Iris
Q.17 Which process converts solid directly into gas without becoming liquid?
Condensation
Sublimation
Evaporation
Melting
Explanation - Sublimation is the process where a solid changes directly into gas without passing through the liquid state.
Correct answer is: Sublimation
Q.18 Which type of energy is stored in food?
Mechanical Energy
Chemical Energy
Electrical Energy
Thermal Energy
Explanation - Food contains chemical energy, which is released during metabolism in the body.
Correct answer is: Chemical Energy
Q.19 Which particle has a negative electric charge?
Proton
Electron
Neutron
Photon
Explanation - Electrons carry a negative charge and orbit the nucleus of an atom.
Correct answer is: Electron
Q.20 Which is the smallest unit of life?
Atom
Molecule
Cell
Organ
Explanation - The cell is the basic structural and functional unit of all living organisms.
Correct answer is: Cell
Q.21 Which vitamin is essential for blood clotting?
Vitamin A
Vitamin K
Vitamin C
Vitamin D
Explanation - Vitamin K is necessary for the synthesis of proteins involved in blood clotting.
Correct answer is: Vitamin K
Q.22 What is the main gas responsible for the greenhouse effect?
Oxygen
Carbon Dioxide
Nitrogen
Hydrogen
Explanation - Carbon dioxide traps heat in the Earth's atmosphere, contributing to the greenhouse effect.
Correct answer is: Carbon Dioxide
Q.23 Which metal is liquid at room temperature?
Mercury
Lead
Iron
Copper
Explanation - Mercury is the only metal that is liquid at room temperature.
Correct answer is: Mercury
Q.24 Which organ in plants is responsible for absorbing water and minerals from the soil?
Root
Stem
Leaf
Flower
Explanation - Roots absorb water and nutrients from the soil and anchor the plant.
Correct answer is: Root
Q.25 Which force keeps planets in orbit around the sun?
Magnetic Force
Gravitational Force
Electrostatic Force
Nuclear Force
Explanation - Gravity from the sun pulls planets towards it, keeping them in orbit.
Correct answer is: Gravitational Force