MCQ Detailed View

The Earth's lithosphere is the rigid outermost layer of the planet, consisting of the crust and the uppermost solid part of the mantle. This layer is broken into 15 major tectonic plates of various sizes. These plates are not fixed; instead, they float and slowly move on the softer, semi-molten layer beneath, known as the asthenosphere.

These tectonic plates include large plates such as the Pacific Plate, North American Plate, Eurasian Plate, African Plate, and others. They also include smaller plates scattered across different parts of the Earth’s surface. The boundaries between these plates are zones of intense geological activity. When plates move or collide, they cause phenomena such as earthquakes, volcanic eruptions, mountain formation, and the creation of oceanic trenches.

The other options given in the question refer to different layers or parts of Earth’s structure:

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  Mesosphere: In Earth science, this usually refers to the middle part of the atmosphere, not the solid Earth.

  
  


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  Stratosphere: Another atmospheric layer located above the troposphere, not related to Earth's crust or tectonic plates.

  
  


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  None: Incorrect because scientists have clearly identified the lithosphere as the layer divided into plates.

  
  

The concept of plate tectonics, first developed in the 20th century, revolutionized geology. It explains how the movement of these plates shapes the planet’s surface over millions of years. Understanding the lithosphere and its division into tectonic plates is essential for studying geology, natural disasters, and environmental changes.

Hence, the correct answer is Lithosphere, the Earth’s solid, outermost shell divided into major and minor plates that drive many natural processes on our planet.