Explanation

Submandible refers to the area under the lower jaw (mandible).

It is close to the ear region.

It contains submandibular glands, which are salivary glands.

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

Perihelion is the point in a comet’s orbit closest to the Sun.

According to Kepler’s Second Law, a comet moves faster when closer to the Sun.

Aphelion is the farthest point from the Sun, where speed is minimum.

The increase in speed is due to Sun’s gravitational pull.

This principle applies to all celestial bodies in elliptical orbits.

Explanation

A cell is the basic structural and functional unit of life.

All plant and animal tissues are made up of cells.

Nitrogen, phosphorus, and oxygen are elements, not units of tissue.

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

• The young ones of a fly hatch from eggs and are worm-like in appearance.
• These young ones are called Maggots.

Additional information:

Stages of a fly’s life cycle (Complete Metamorphosis):

• Egg – laid on decaying organic matter
• Maggot (larva) – feeding stage
• Pupa – transformation stage
• Adult fly – reproductive stage
• Common fly species – Housefly, Blowfly, Fruit fly

Last verified on 24-01-2026

Explanation

• Insects with complete metamorphosis pass through four stages: egg → larva → pupa → adult.
• The pupa stage is when the insect transforms inside a cocoon or protective casing.

Additional information:

• Pupa stage is also called the resting stage or chrysalis stage

Last verified on 24-01-2026

Explanation

• A flower is made of different parts: Calyx, Corolla, Androecium, and Gynoecium.
• Petals are usually colorful and fragrant to attract pollinators.
• All petals together form a distinct part called the Corolla.

Additional information:

• Calyx is made of sepals, usually green, protecting the bud.
• Gynoecium is the female reproductive part of a flower (carpel/pistil).

Last verified on 23-01-2026

Explanation

• Nutrients required by plants are classified into primary, secondary, and micronutrients.
• Primary nutrients: Nitrogen (N), Phosphorus (P), Potassium (K).

Additional information:

• Secondary nutrients: Calcium (Ca), Magnesium (Mg), Sulfur (S).
• Calcium strengthens cell walls and helps in growth of root and shoot tips.

Last verified on 23-01-2026

Explanation

• Photosynthesis is an endogenic process in plants, meaning it produces energy-rich compounds.
• Requires light, water, and carbon dioxide to produce glucose and oxygen.

Additional information:

• Formula: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
• Occurs in chloroplasts, primarily using chlorophyll pigments.

Last verified on 23-01-2026