Explanation

• Date: 27 October
• Observed as: Kashmir Black Day
• First observed Year: 1947
• Purpose: To mark the arrival of Indian troops in Srinagar.

Explanation

• Vitamin C deficiency → Scurvy
• Causes bleeding gums and poor wound healing.
• Vitamin C is important for collagen formation.
• Main sources: Citrus fruits, guava, tomatoes, and vegetables.

Last verified on 02-11-2026

Explanation

• Iodine deficiency causes goiter, an enlargement of the thyroid gland.
• Iodine is essential for the production of thyroid hormones.
• Severe iodine deficiency during pregnancy or early childhood can impair brain development.

Last verified on 07-09-2026

Explanation

• Blue light has the shortest wavelength.
• In the visible spectrum, wavelength decreases from red to violet.

Additional information:

• Red light rays have the lowest frequency and highest wavelength value.

Last verified on 10-06-2026

Explanation

• All electromagnetic waves travel through a vacuum at 3x10^8 m/s.
• This is the speed of light (c).
• Radio waves, microwaves, visible light, X-rays and gamma rays all have the same speed in vacuum.

Last verified on 31-10-2026

Explanation

• Pertinent means متعلقہ
• Irrelevant means غیر متعلقہ

Explanation

• The phrase "so that" followed by "might" shows purpose in the past.
• "I got up early so that I might cover..." is grammatically correct and formal in tone.

Last verified on 31-10-2026

Explanation

• Restriction enzymes are also called molecular scissors because they cut DNA at specific recognition sequences.
• They recognize particular short DNA sequences, often 4–8 base pairs long.
• These enzymes may produce sticky ends or blunt ends after cutting DNA.
• They are widely used in genetic engineering, recombinant DNA technology, and gene cloning.
• Example: EcoRI is a restriction enzyme that recognizes the sequence GAATTC.

Last verified on 31-10-2026

Explanation

• During photosynthesis, water molecules are split in the light-dependent reactions. This process is called photolysis.
• The oxygen released into the atmosphere comes from water (H₂O).
• The splitting of water also provides electrons and hydrogen ions needed for photosynthesis.

Last verified on 31-10-2026

Explanation

• Alt + Shift + F1 / Shift + F11 → Insert a new worksheet

Additional information:

• Shift + F10 → Open shortcut/context menu
• Ctrl + Page Up → Previous worksheet
• Ctrl + Page Down → Next worksheet

Last verified on 15-07-2026