Reference section
Acceleration
Change of speed –
speeding up or slowing down.
Alpine
Areas on a mountain
side that are above the trees but
below the permanent snow.
Alveoli
Tiny air sacs inside
your lungs.
Amphibian
An animal that
can live on land or in water.
Ancestor
Someone you are
related to who lived a long
time ago.
Astronaut
A person who
is trained to travel into space.
Astronomy
The study of
the universe.
Atmosphere
The thin layer
of gas that surrounds a planet.
Bacterium (plural:
bacteria)
A living thing with
just one cell. Bacteria are found all
over the world – in the oceans, on
land, in plants, and in our bodies.
Carnivore
An animal that
eats meat. Lions are carnivores.
Cell
A tiny unit that is the basic
building block of all living things.
Chlorophyll
The chemical in
plants that makes them green. It
is essential for photosynthesis.
Chromosome
A rod-shaped
strand containing DNA, found
in the nucleus of a cell.
Civilization
The way of life
of a group of people living in a
particular area – ancient Greek
civilization, for example.
Condensation
Changing from
a less dense state, such as a gas,
into a more solid state, such as
a liquid – for example, water
vapour condenses into water.
Continent
A large area of land,
usually divided into different
countries. Europe is a continent.
Decibel
The unit of
measurement for sound.
Deciduous
A plant that loses
many or all its leaves in one season
each year. Oak and maple trees
are deciduous.
Decomposition
The breaking
down (decaying) of dead animals
and plants into smaller pieces, and
recycling them into nutrients.
Dermis
The deepest layer of
skin, which contains nerves and
blood vessels.
Diaphragm
The muscle under
your lungs that moves up and
down as you breathe.
Digestion
The system that
breaks down and absorbs food so
your body can use it for energy
and to make new cells.
DNA
A chemical inside your
body that contains the instructions
for making living cells.
Ecosystem
A community of
plants and animals living and
interacting with each other and
their immediate environment.
Epidermis
The top layer of
skin, which you can see.
Equator
The imaginary line
around the middle of the world.
Era
A period of time in history.
Estuary
The place where a river
meets the sea.
Glossary
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