Explanation

• Solar and wind energy are renewable sources of energy, meaning they are sustainable and will not run out.
• Solar energy is generated from the sun's rays.
• Wind energy is generated from the wind.

Last updated 08 Nov 2026 by NA

Explanation

• Vitamin A deficiency → Night blindness (Nyctalopia)
• Vitamin A is important for vision and immune function.

Additional information:

• Vitamin K is essential for blood clotting.
• Vitamin D helps in calcium absorption and bone mineralization.
• Vitamin B1 supports nerve function and energy metabolism.

Last verified on 01-02-2026

Explanation

• Our Solar System is located in the Orion Arm of the Milky Way galaxy.
• It including the Sun and eight planets.
• It consists of about 100–400 billion stars along with large amounts of gas and cosmic dust.

Additional information:

• The Milky Way is a spiral galaxy with a diameter of about 100,000 light-years.
• The nearest large galaxy to the Milky Way is Andromeda, located about 2.5 million light-years away.

Last verified on 11-03-2026

Explanation

• The study of ancient societies through remains and artifacts is called archaeology.
• It focuses on ruins, tools, coins, and old structures.
• It helps us understand past human civilizations.

Last verified on 02-05-2026

Explanation

• The Sun is a star at the center of our solar system with a surface temperature of about 6000 °C (Sun’s core is even hotter, ~15 million °C).
• It provides light and heat, essential for life on Earth.
• The Sun’s energy drives weather, photosynthesis, and climate.

Last verified on 18-03-2026

Explanation

• The term Geography was first used by the Greek scholar Eratosthenes.
• He lived in the 3rd century BC (around 276–194 BC).
• He is also known as the “Father of Geography”.
• He calculated the circumference of the Earth with remarkable accuracy.
• His work laid the foundation of modern geographical studies.

Last verified on 02-05-2026

Explanation

• Titan is the largest moon of Saturn.
• It is also the second-largest moon in the solar system after Ganymede.
• It has a thick atmosphere mainly of nitrogen.
• Titan is larger than the planet Mercury in size.

Last verified on 02-05-2026

Explanation

• Whales evolved from land-dwelling mammals.
• Their ancestors gradually adapted to aquatic life.
• Over millions of years, they moved from land to sea.
• They developed flippers instead of legs for swimming.
• This is an example of evolution and adaptation.

Last verified on 26-04-2026

Explanation

• Edward Jenner was an English physician and scientist.
• He discovered the first vaccine for smallpox in 1796.
• He observed that milkmaids infected with cowpox were protected from smallpox.
• This led to the development of vaccination (cowpox-based immunity method).
• He is known as the Father of Immunology.

Last verified on 02-05-2026

Explanation

• Digestion begins in the mouth, starting immediately when food is ingested.
• Both mechanical digestion (chewing) and chemical digestion (salivary amylase breaking down carbohydrates) 

Additional information:

• Mouth: Food is chewed and mixed with saliva that contains enzymes to break down carbohydrates.
• Esophagus: Food is swallowed and passes through the esophagus into the stomach.
• Stomach: Food is mixed with stomach acid and enzymes to break down proteins and fats.
• Small Intestine: Nutrients are absorbed into the bloodstream.
• Large Intestine: Water and electrolytes are absorbed, and waste is eliminated.

****

Last updated by NS on 01 MAY 2026