What is the lithosphere?

The lithosphere is the solid outermost layer of the Earth. It includes the land masses (continents) and the solid floors of the oceans.

Which is the largest ocean and which is the largest continent?

The Pacific Ocean is the largest and deepest ocean, and Asia is the largest continent.

The biosphere is the narrow zone of the Earth where the land, water and air interact and together support life — it is the home of all living things.

Exercise Solutions Available

Step-by-step answers for all textbook questions in this chapter

The Earth is made up of four major domains, or realms:

Domain	Made of
Lithosphere	Solid part — land and ocean floor
Atmosphere	The thin layer of air around the Earth
Hydrosphere	All the water on the Earth
Biosphere	The narrow zone where land, water and air meet and support life

The lithosphere is the solid outermost layer of the Earth.
It includes the continents (large landmasses) and the ocean floors.
The lithosphere is not one single shell — it is broken into large pieces called plates that move very slowly.

The atmosphere is the thin layer of air that surrounds the Earth.
It is made up of gases — mainly nitrogen and oxygen, with small amounts of carbon dioxide and others.
It protects us from the Sun's harmful rays, keeps the Earth warm enough for life, and gives us the air we breathe.
The atmosphere has layers, with the air getting thinner as we go higher.

The hydrosphere is the total water on the Earth — oceans, seas, rivers, lakes, ice and underground water.
About 71% of the Earth's surface is covered with water, which is why it looks blue from space.

The biosphere is the narrow zone where the lithosphere, hydrosphere and atmosphere meet and interact.
This is the part of the Earth where life exists — plants, animals and human beings all live in the biosphere.

The large landmasses on the Earth are called continents. There are seven:

Continent	Size note
Asia	Largest continent
Africa	—
North America	—
South America	—
Antarctica	Covered with thick ice all year
Europe	—
Australia	Smallest continent

The Asia–Europe landmass together is sometimes called Eurasia. Antarctica is so cold that people do not live there permanently.

The huge bodies of water between continents are called oceans. There are five:

Ocean	Note
Pacific Ocean	Largest and deepest; almost equal in size to all the others together
Atlantic Ocean	Roughly "S" shaped; very busy for trade
Indian Ocean	Triangular in shape; named after India
Southern (Antarctic) Ocean	Surrounds Antarctica
Arctic Ocean	Smallest and coldest, near the North Pole

Term	Meaning
Domain	A major realm of the Earth
Lithosphere	The solid part — land and ocean floor
Atmosphere	The layer of air around the Earth
Hydrosphere	All the water on the Earth
Biosphere	The zone of life where land, water and air meet
Continent	A very large landmass
Ocean	A very large body of salt water
Plate	A large piece of the broken lithosphere

The four domains in order — lithosphere, atmosphere, hydrosphere, biosphere — is a standard short-answer question.
71% of the Earth is water (hydrosphere); this also explains why it is the Blue Planet.
Asia = largest continent, Australia = smallest; Pacific = largest/deepest ocean, Arctic = smallest — both pairs are commonly asked.
The biosphere is where all three other domains interact — say this clearly to score full marks.
The atmosphere's two main gases are nitrogen and oxygen.

The four major domains are the lithosphere (solid land), the atmosphere (air), the hydrosphere (water) and the biosphere (the zone of life).