Explanation

• Ethylene is a gaseous plant hormone that stimulates fruit ripening.
• It can inhibit vegetative growth in some plants.
• It is naturally produced by fruits like apples and bananas during maturation.

Additional information:

• Abscisic acid helps in seed dormancy and stress response.
• Auxin mainly promotes cell elongation and growth.

Last verified on 30-01-2026

Explanation

• A wind vane (also called a weather vane) shows the direction from which the wind is blowing.
  • Usually installed on rooftops or meteorological stations.
  • Works with a rotating pointer that aligns with the wind direction.

Last verified on 01-02-2026

Explanation

• Horticulture means پھول، جڑی بوٹیاں، پھل اور سبزیاں کاشت کرنے کا علم
• Horticulture is the agriculture of plants.
  
  
  
  Additional information:
  • Agrostology: Study of grasses 
  • Agronomy: Soil management and crop production 
  • Odontology: Study of teeth 
  • Arthrology: Study of joints 
  • Nephrology: Study of kidneys
  • Hematology: Study of blood  
  • Dermatology: Study of skin

Last verified on 30-01-2026

Explanation

• A hydrometer is an instrument used to measure the specific gravity of liquids.
• It works based on the principle of buoyancy.
• It is widely used to test milk, alcohol, and battery acid.
• Commonly used in laboratories and industries.

Last verified on 30-01-2026

Explanation

• Urea fertilizer contains 46% nitrogen (N).
• Urea is a white crystalline solid.
• It is widely used as a fertilizer and animal feed additive.

Last verified on 31-01-2026

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

• Germ Theory of Disease states that microorganisms (germs) cause diseases.
• Proposed by Louis Pasteur (1822–1895), a French scientist.
• This theory revolutionized medicine, leading to vaccines and sterilization methods.

Additional information:

• Robert Koch later developed techniques to identify specific germs for specific diseases.

Last verified on 29-01-2026

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 seed coat protects the embryo inside the seed.
• The outermost layer of the seed coat is called Testa.
• It acts as a barrier against mechanical damage, pathogens, and water loss.

Additional information:

• Testa may have hair, wax, or spines in some seeds.
• Plays a role in seed dormancy and protection.

Last verified on 25-01-2026

Explanation

• Plants can respond to various stimuli like light, gravity, and touch.
• The response of plants to touch is called thigmotropism.
• It is commonly seen in climbing plants and vines, which coil around supports.

Last verified on 23-01-2026