Explanation

• Continetal Drift theory was proposed by Alfred wegner in 1912.
• It stated that continents have changed their position and initially there was only one big continent named Pangea.
• Although he was unable to explain the force behind the drifting of continents.

Last verified on 12-11-2026

Explanation

• The Earth's outermost layer is called the Crust.
• The crust is the thin, solid outer layer where humans, animals, and plants live.
• It is located above the mantle, outer core, and inner core.
• It is made mainly of rocks and minerals.

Additional information:

• Earth's Layers (Outer to Inner): Crust → Mantle → Outer Core → Inner Core
• Crust Thickness: About 5–70 km
• Mantle Thickness: About 2,900 km
• Outer Core Thickness: About 2,260 km
• Inner Core Radius: About 1,220 km

Last verified on 04-08-2026

Explanation

Explanation

Explanation

• The notochord is a flexible, rod-shaped structure that is present during the embryonic stage of all chordates
• It provides support and defines the primitive axis of the body.
• This characteristic is a key feature that distinguishes chordates from non-chordates.

Last verified on 06-11-2026