Explanation

• Ibn al-Haytham is known as the Father of Modern Optics.
• He made groundbreaking discoveries about light and vision.
• His famous book is Kitab al-Manazir (Book of Optics).
• His research was done around 1011–1021 AD.

Last verified on 27-04-2026

Explanation

• Battery is a device that converts chemical energy into electrical energy.
• Batteries work by using a galvanic cell.
• It is an electrochemical device made up of two electrodes and an electrolyte solution.

Last verified on 16-03-2026

Explanation

• Insulin is produced by the pancreas.
• The pancreas contains clusters of cells called the Islets of Langerhans.
• Beta (β) cells within these islets produce and secrete insulin.
• Insulin helps regulate blood glucose (sugar) levels by promoting glucose uptake into cells.

Last verified on 07-09-2026

Explanation

Earth's Rotation 

• - Sidereal Day: Approximately 23 hours, 56 minutes, 4 seconds.
• - Meaning: The time Earth takes to rotate once relative to distant stars.
• - Solar Day: Approximately 24 hours, measured from one noon to the next.
• - Difference: About 4 minutes.

Last updated 08 Nov 2026 by NA

Explanation

• Chlorophyll is the green pigment responsible for photosynthesis in plants.
• It captures sunlight and converts it into chemical energy to make food.

• Plants use chlorophyll to produce glucose and oxygen through photosynthesis.
• Chloroplasts contain chlorophyll a and b, which absorb sunlight.

Last verified on 22-01-2026

Explanation

• Plants need gas exchange for photosynthesis and respiration.
• Exchange of CO₂, O₂, and water vapor occurs through stomata on leaves.
• Stomata are tiny pores controlled by guard cells.

Additional information:

• Helps maintain internal water balance and gas diffusion.
• Essential for growth, energy production, and transpiration.

Last verified on 22-01-2026

Explanation

• The cell cycle is the sequence of stages a cell goes through to grow and divide.
• DNA synthesis (replication) occurs during the S Phase (Synthesis Phase).

Additional information:

1. G₁ Phase – cell growth before DNA replication
2. G₂ Phase – preparation for cell division after DNA replication
3. M Phase – actual mitosis/cell division

Last verified on 22-01-2026

Explanation

• The stomach produces Hydrochloric Acid (HCl) as part of gastric juice.
• HCl creates a highly acidic environment with a pH of about 1.5–3.5.
• It activates pepsinogen into pepsin.
• Pepsin helps break down proteins into smaller peptides.

Last verified on 03-09-2026

Explanation

• The SI unit of energy is the Joule (J).
• It is the unit of energy, work, and heat.

Additional information:

• 1 Joule (J) = 1 Newton × 1 meter
• Calorie – 1 cal = 4.184 J
• Kilowatt-hour (kWh) – 1 kWh = 3.6 × 10⁶ J
• Electronvolt (eV) – 1 eV ≈ 1.602 × 10⁻¹⁹ J
• Erg (CGS unit) – 1 erg = 10⁻⁷ J

Last verified on 17-01-2026

Explanation

• Alexander Graham Bell is credited as the inventor of the telephone.
• He was awarded the first successful patent for it.
• The telephone was invented in 1876.
• Bell made the first-ever telephone call to his assistant Thomas Watson.

Last updated by NA on 06-11-2026