Explanation

• Clayey soil has very fine particles and a large surface area.
• It can hold more water.

Additional information:

• Silty — moderate water retention
• Loamy — balanced water retention and drainage
• Sandy — low water retention, drains quickly
• Stony — very low water retention

Last verified on 12-02-2026

Explanation

Explanation

• Urea fertilizer is a nitrogenous fertilizer (CO(NH₂)₂).
• It has a slightly alkaline nature with pH around 8.0.

Additional information:

• Ammonium sulfate — 5.0–6.0 (acidic)
• DAP — 7.0–7.5 (neutral to slightly alkaline)
• MOP — 7.0–8.0 (neutral to slightly alkaline)
• SSP — 5.5–6.5 (slightly acidic)

Last verified on 12-02-2026

Explanation

• Number of linkage groups = number of chromosome pairs (haploid number).
• Maize has 10 pairs (2n = 20) chromosomes.
• Haploid number (n) = 10.

Additional information:

• Wheat (bread) — 21 pairs → 21 groups
• Pea — 7 pairs → 7 groups
• Rice — 12 pairs → 12 groups
• Human — 23 pairs → 23 groups

Last verified on 12-02-2026

Explanation

• DNA contains a pentose sugar called deoxyribose.
• Pentose means the sugar has 5 carbon atoms.
• It forms the backbone of the DNA structure.
• Joined with phosphate and nitrogenous bases.
• Essential for genetic information storage.

Last verified on 12-02-2026

Explanation

• Ribosomes are known as the "protein factories" of the cell.
• They assemble amino acids into proteins according to mRNA instructions.

Last verified on 12-02-2026

Explanation

• A nullisomic individual lacks both chromosomes of one homologous pair.
• Therefore its chromosome number is 2n − 2.
• It is a type of aneuploidy.

Additional information:

• Monosomic — 2n − 1
• Trisomic — 2n + 1
• Tetrasomic — 2n + 2
• Euploid — normal 2n

Last verified on 12-02-2026

Explanation

• Heritability measures how much of trait variation is due to genetics.
• Narrow-sense heritability = Additive genetic variance / Phenotypic variance.
• It shows how well a trait can be passed from parents to offspring.
• Important in plant and animal breeding.
• Helps predict response to selection.

Last verified on 12-02-2026

Explanation

• Kajli is a well-known sheep breed of Pakistan.
• Famous for its high-quality wool and meat.
• Primarily found in Punjab and Sindh regions.
• Adapted to local climatic conditions.
• Important for livestock economy and farmers’ income.

Last verified on 12-02-2026

Explanation

• Soil texture refers to the relative proportion of sand, silt, and clay particles in soil.
• Determines water retention, aeration, and fertility of soil.
• Soil structure is about arrangement of soil particles.
• Important for agriculture and land management.

Last verified on 12-02-2026