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

The main source of energy in stars is nuclear fusion.

It is the process of combining atomic nuclei (usually hydrogen nuclei) to form a heavier nucleus, releasing vast amounts of energy in the process.

This energy is what makes stars shine.

Explanation

The ozone layer is a region within the stratosphere, extending from about 15 to 30 km (9 to 19 miles) above the Earth's surface.

It contains a high concentration of ozone (O3), a molecule made up of three oxygen atoms. 

The ozone layer plays a crucial role in protecting the Earth from harmful ultraviolet (UV) radiation from the sun, particularly UV-C and UV-B rays.

Explanation

Homeostasis is the set of metabolic reactions that maintain the internal environment of an organism, regulating factors.

Such as temperature, pH, blood sugar levels, and blood pressure.

Explanation

Explanation

The skin is considered the largest organ of the human body.

It covering an area of about 1.5-2 square meters (16-22 square feet).

It weighing around 3-4 kilograms (7-9 pounds).

Explanation

Amphoteric substances are those that can react with both acids and bases.

They can donate or accept protons (H+ ions), depending on the conditions.

Examples of amphoteric substances include water (H2O), amino acids, and certain metals like zinc and aluminum.

Explanation

Alpha (α) radiation consists of heavy, positively charged particles (alpha particles) that are emitted from the nucleus of an atom during certain types of radioactive decay.

Alpha particles are highly ionizing, meaning they can efficiently remove tightly bound electrons from atoms, resulting in the formation of ions.

Explanation

Chondrocytes are the cells that make up cartilage, a type of connective tissue found in various parts of the body, such as joints, ears, nose, and ribs.

Chondrocytes produce and maintain the cartilage matrix, which consists of collagen and proteoglycans.

Explanation

An atom consists of three subatomic particles:

1. Protons (positively charged)
2. Neutrons (neutral)
3. Electrons (negatively charged)

Additional Information:

A neutral atom has equal protons and electrons; imbalance creates ions.

Discovered by John Dalton in 1808 (Atomic Theory).

Cation = positive ion,
Anion = negative ion,
Isotopes = same element with different neutrons,