Explanation

• Bacillus thuringiensis (Bt) is a soil-dwelling bacterium used as a natural bio-pesticide.
• Produces toxins harmful to insect larvae, especially caterpillars and mosquitoes.

Additional information:

• Discovered in 1901 by Japanese scientist Shigetane Ishiwata.
• Widely used in organic farming to control pests without harming humans, animals, or plants.

Last verified on 20-01-2026

Explanation

• Guttation is the process where water droplets appear on leaf edges due to root pressure.
• It usually occurs at night or early morning when soil moisture is high and transpiration is low.
• Common in plants like grapevine, tomato, and grasses.

Last verified on 20-01-2026

Explanation

• Pakistan’s soils vary due to climate, topography, and irrigation practices.
• Major soil orders found in Pakistan include Aridisol, Inceptisol, and Entisol.

Additional information:

• Aridisols dominate in arid and desert regions (e.g., Thar Desert).
• Inceptisols are found in flood plains and irrigated areas.
• Entisols occur in recently deposited alluvial soils near rivers.

Last verified on 20-01-2026

Explanation

• Red rot is a major fungal disease of sugarcane caused by Colletotrichum falcatum.
• Mostly affects mature, thick sugarcane stalks.

Additional information:

• Red rot is more severe in stressed or old crops.
• Symptoms include reddish streaks in cane, white fungal growth inside, and bad smell.

Last verified on 20-01-2026

Explanation

• Strawberry is classified as an aggregate fruit.
• The tiny seeds (achenes) on the surface are the true fruits.

Additional information:

• Examples of aggregate fruits: Strawberry, Raspberry, Blackberry.
• Strawberries are rich in vitamin C and antioxidants.

Last verified on 20-01-2026

Explanation

• The lipid membrane is rigid, providing a protective barrier against chilling and environmental stress.
• Flexible or liquid membranes do not effectively prevent chilling injury.

Additional information:

• The cuticular wax layer contributes to rigidity.
• Helps maintain fruit and vegetable shelf life during storage.

Last verified on 20-01-2026

Explanation

• Waterlogged soils have a massive structure, meaning they form large, hard clods with little visible granular structure.
• This occurs because water pressure compacts soil particles at the surface.

Additional information:

• Massive soils have low permeability and poor aeration.
• Proper drainage and puddling can improve rice yield in such soils.

Last verified on 20-01-2026

Explanation

• Citrus trees in tropical regions are mostly evergreen.
• They retain and grow leaves throughout the year due to consistent warm climate.
• Seasonal changes have minimal effect on their leaf growth.

Additional information:

• Examples of citrus trees: Orange, Lemon, Lime, Grapefruit.
• Evergreen nature helps in continuous photosynthesis and fruit production.

Last verified on 20-01-2026

Explanation

• Nutritive foods supply the body with necessary nutrients for growth, energy, and repair.
• They include all food groups that contribute to balanced nutrition.

Additional information:

• Cereals provide carbohydrates for energy.
• Vegetables and fruits provide vitamins and minerals.
• Meat provides proteins and iron for body-building.

Last verified on 20-01-2026

Explanation

• Soybean plants have dense root systems that bind soil particles, reducing erosion.
• It is commonly used in crop rotation and soil conservation programs.

Additional information:

• Other soil-conserving crops include clover, alfalfa, and grasses.
• Planting cover crops also improves soil fertility and prevents weed growth.

Last verified on 20-01-2026