Explanation

The Earth was formed about 4.5 billion years ago.

Additional information:

• Method Used: Radiometric dating
• Oldest Materials: Meteorites and ancient Earth rocks
• Scientific Consensus: Supported by geology and astronomy

Last verified on 16-01-2026

Explanation

• Sunlight is a good source of vitamin D.
• When our skin is exposed to sunlight, it produces vitamin D, 
• It is essential for bone health, immune function, and the regulation of calcium levels in the blood.
• Deficiency of Vitamin D results in Rickets.

Explanation

Chromosomes are made up of:

• Nucleic acid (DNA or RNA)
• Proteins (histones and non-histone proteins)

A chromosome is made up of proteins and DNA organized into genes.

Each cell normally contains 23 pairs of chromosomes.

Explanation

• Apiculture is the practice of rearing honeybees for honey and wax production.
• Helps in pollination and increasing crop yields.
• Honey, beeswax, and propolis are valuable products from apiculture.

• Sericulture → Rearing of silk worms.
• Silviculture → Cultivation of trees and forests.

Last verified on 30-01-2026

Explanation

• Nitrobacter bacteria convert nitrite (NO₂⁻) into nitrate (NO₃⁻) in the soil.
• This is the second step of the nitrification process, which is important for plant nutrition.
• Nitrite is toxic to plants, but nitrate is easily absorbed as a nutrient.

Last verified on 22-01-2026

Explanation

• The young ones of a fly hatch from eggs and are worm-like in appearance.
• These young ones are called Maggots.

Additional information:

Stages of a fly’s life cycle (Complete Metamorphosis):

• Egg – laid on decaying organic matter
• Maggot (larva) – feeding stage
• Pupa – transformation stage
• Adult fly – reproductive stage
• Common fly species – Housefly, Blowfly, Fruit fly

Last verified on 24-01-2026

Explanation

• Insects with complete metamorphosis pass through four stages: egg → larva → pupa → adult.
• The pupa stage is when the insect transforms inside a cocoon or protective casing.

Additional information:

• Pupa stage is also called the resting stage or chrysalis stage

Last verified on 24-01-2026

Explanation

• A flower is made of different parts: Calyx, Corolla, Androecium, and Gynoecium.
• Petals are usually colorful and fragrant to attract pollinators.
• All petals together form a distinct part called the Corolla.

Additional information:

• Calyx is made of sepals, usually green, protecting the bud.
• Gynoecium is the female reproductive part of a flower (carpel/pistil).

Last verified on 23-01-2026

Explanation

• Nutrients required by plants are classified into primary, secondary, and micronutrients.
• Primary nutrients: Nitrogen (N), Phosphorus (P), Potassium (K).

Additional information:

• Secondary nutrients: Calcium (Ca), Magnesium (Mg), Sulfur (S).
• Calcium strengthens cell walls and helps in growth of root and shoot tips.

Last verified on 23-01-2026

Explanation

• Photosynthesis is an endogenic process in plants, meaning it produces energy-rich compounds.
• Requires light, water, and carbon dioxide to produce glucose and oxygen.

Additional information:

• Formula: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
• Occurs in chloroplasts, primarily using chlorophyll pigments.

Last verified on 23-01-2026