Page 189 - Innovator's Science-8

THE LIVING PLANET – HOW EARTH SUSTAINS LIFE

Earth offers the right conditions for life, but what truly enables life to thrive
is the intricate connection between living and non-living things. previous
classes, you explored important natural resources such as air, water
sunlight, soil, and minerals. You also learned how plants and animals carry

out vital life processes.
In this section, we’ll delve into how all these elements work together in

harmony, creating a balanced system that nurtures and sustains life on our
remarkable planet.

Air, Water, and Sunlight Water

The Earth’s atmosphere contains oxygen,
Science which is essential for the survival of O 2
Bytes
humans, animals, and plants. In the Light energy Oxygen
Testimony
The oxygen we breathe presence of sunlight, plants use carbon
today is the result of dioxide from the air and water from the
billions of years of soil to prepare food through
photosynthesis. Early CO 2
microscopic organisms photosynthesis. This process also releases Carbon dioxide Sugar
called cyanobacteria were oxygen back into the air.
the first to release oxygen
into Earth's atmosphere The Sun plays a key role in heating our Minerals
H O
2
about 2.5 billion years planet. Some of this heat is trapped by Water
ago. This slow
transforma on turned gases in the atmosphere— a natural
the planet's once toxic air process known as the greenhouse effect. Photosynthesis
into the life suppor ng This effect, though gentle, keeps Earth warm enough for water to remain in
atmosphere we depend
on today! liquid form, making life possible. Without the atmosphere, the planet
would lose heat to space and become too cold to sustain life.

Water is another essential component for life. It covers around 70% of
Earth’s surface and is found in lakes, rivers, oceans, ponds, springs, and
underground reserves. Together, all this water forms what we call the

hydrosphere.

Water serves many functions— it acts as a solvent, transports nutrients in
Life in water plants, regulates body temperature ir animals, aids in digestion, and keeps
organisms hydrated. Even though Earth is mostly covered by water, much of
the deep ocean remains unexplored. This underwater world supports a
vast range of life from microscopic plankton to enormous whales– with

many species yet to be discovered. Freshwater is also vital for growing
crops and meeting the needs of people around the world.

Water vapour in the atmosphere forms clouds and brings rain or snow,

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