Explanation

• The instrument used to measure temperature is called a thermometer.
• A thermometer shows how hot or cold an object or place is.

Additional information:

• Barometer measures air pressure.
• Hygrometer measures humidity (moisture in air).

Last verified on 16-06-2026

Explanation

• Boiling point of water: 100°C
• Freezing point of water: 0°C
• Standard atmospheric pressure: 1 atm (760 mmHg)
• 0°C = 32°F
• 100°C = 212°F

Last verified on 06-07-2026

Explanation

• Sound cannot travel through a vacuum because there are no particles to carry sound vibrations.
• Sound needs a medium such as a solid, liquid, or gas to travel.
• Since space is nearly a vacuum, sound cannot be heard there.
• The speed of sound in a vacuum is 0 m/s.

Additional information:

• Infrasound: Below 20 Hz
• Audible sound: 20 Hz – 20,000 Hz (20 kHz)
• Ultrasound: Above 20 kHz
• Speed of sound in air: 343 m/s
• Speed of sound in water: 1,481 m/s

Last verified on 07-06-2026

Explanation

• Proteins are called body-building foods.
• They help in growth, repair of tissues, and muscle development.
• They are essential for maintaining and rebuilding body cells.
• They are made of amino acids, the building blocks of the body.
• Deficiency of protein can lead to weak muscles and poor growth.

Last verified on 06-05-2026

Explanation

• Vitamin D is essential for healthy bones.
• Its deficiency leads to Rickets in children and Osteomalacia in adults.
• Sunlight is the best natural source of Vitamin D.

Additional information:

Deficiency effects:

• Bone pain
• Weak bones
• Skeletal deformities

Other Vitamin Deficiencies:

• Vitamin A: Night blindness
• Vitamin C: Scurvy
• Vitamin B7 (Biotin): Hair fall

Last verified on 17-01-2026

Explanation

• Carbohydrates are the fastest and main source of energy.
• They are quickly converted into glucose in the body.
• Glucose is used immediately for energy production.
• They provide instant fuel for brain and muscles.

Last verified on 14-05-2026

Explanation

• Vitamin D is essential for strong bones and teeth.
• It helps the body absorb calcium and phosphorus.
• Its deficiency causes Rickets in children.
• Vitamin D = “Sunshine vitamin”
• Helps in bone mineralization
• Works with calcium to build strong skeleton

Last verified on 07-05-2026

Explanation

• Total bones in adult human body = 206
• At birth = 270–300 bones (fuse to become 206)

The total bones of our body can be divided into:

• Axial skeleton = 80 bones
• Appendicular skeleton = 126 bones

Additional information:

• Newborn baby has 300 bones
• Longest bone = Femur
• Shortest bone = Stapes
• Bones in human skull = 22

Last verified on 30-03-2026

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.

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Last updated by NS on 01 MAY 2026

Explanation

• Vitamin A is essential for vision, skin health, and immune function.
• Its deficiency can lead to night blindness (poor ight vision) and other health problems.

Additional information:

• Dry skin and eyes
• Impaired immune function
• Poor wound healing
• Increased risk of respiratory and urinary tract infections

Last verified on 17-01-2026