Glossary
Evaporation
The changing of
a liquid to a gas.
Evergreen
A plant that has
leaves on it throughout the year.
Extinct
An animal or plant that
has completely disappeared from
our world.
Fault
A place where the Earth’s
crust has cracked and moved.
Fertilization
The joining of a
male cell and a female cell to start
growing a baby OR improving soil
by adding nutrients to it.
Fossil
The remains of a plant
or animal that has died and been
preserved in rock.
Fossil fuels
A fuel such as
coal, oil, or natural gas that
was formed underground millions
of years ago from the remains of
dead plants and animals.
Friction
A force that makes
things slow down. When two solids
rub against each other, or when a
solid moves through liquid or gas,
it causes friction.
Galaxy
A large rotating system
of stars, gas, dust, and empty
space held together by gravity.
Gene
Part of your DNA, genes
contain chemical information
that controls the way your body
develops and works. Genes pass
from parents to their children.
Germ
Tiny living thing (micro-
organisms) found everywhere
including inside our bodies.
Bacteria are germs. Some germs
are good, but some are bad and
make us ill.
Geyser
A naturally occurring
hot spring, where occasionally
the water boils and shoots up
in a big spurt.
Glacier
A huge river of ice.
Gladiator
In Roman times, a
man trained to fight other men or
wild animals in an arena while
others watched.
Gravity
The attraction between
everything in the universe. Gravity
makes the moon rotate around the
Earth, and the Earth and other
planets rotate around the Sun.
Habitat
The natural home of
an animal or plant.
Herbivore
An animal that
eats mainly plants. Giraffes
are herbivores.
Hibernation
When animals
rest through the winter. They
normally find somewhere warm
and dry and sleep throughout the
cold season.
Hieroglyphics
An ancient
Egyptian method of writing that
uses symbols.
Hydrosphere
All the water
on the Earth’s surface, including
ice, and water vapour in the
atmosphere.
Immune system
The cells and
tissues in your body that protect
it from infection. If you do get an
illness, your immune system often
creates special defences so you
don’t get the same illness again.
Inertia
The tendency
everything has to avoid
movement or change.
Infrared radiation
Heat
energy that is given off by all
solids, liquids, and gases.
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