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A
Acid: A chemical that has a sour taste. Acids react
with bases, and strong acids are corrosive.
Acids have a pH less than 7.
Air resistance: The friction from air when you
move through it.
Algae: Aquatic photosynthetic organism that differs f
rom plants in not having true leaves, roots, or
stems.
Alkali: A chemical that dissolves in water and reacts
with an acid. Alkalis have a pH greater than 7.
Amplitude: The height of a vibration. A sound with
large amplitude is loud.
Antacids: Medicine for acid indigestion that
neutralizes excess stomach acid.
B
Base: A chemical that reacts with an acid. Soluble
bases are called alkalis.
Budding: A type of asexual reproduction found in
corals where a bud grows from the parent
polyp.
C
Carbohydrates: A type of food made by plants in
their leaves.
Carbon dioxide: A colourless odorless atmospheric
gas produced during respiration and used by
plants during photosynthesis.
Carbon monoxide: A colourless, odourless and
poisonous gas produced by the incomplete
combustion of carbon compounds.
Cells: The ‘building blocks’ that all things are made
of.
Chlorofluoro carbon: Chemicals used in aerosol
sprays that can cause the thinning of the ozone
layer in our atmosphere.
Chloroplast: Packets of green colour in plants leaves
which trap light energy to make food.
Circuit diagram A map of an electrical circuit using
special symbols for all the components.
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Compound: A substance made of two or more
different kinds of atoms chemically joined
together.
Constipation: A condition in which a person or animal
has difficulty in eliminating solid waste from the
body and the feces are hard and dry.
Convection: Circulatory movement in liquid or gas,
resulting from regions of different temperatures
and different densities rising and falling in
response to gravity.
Cotyledons: The first leaf, or one of the first pair of
leaves, produced by the seed of a flowering plant.
Coral Polyp: A marine organism that lives in
colonies and has an external skeleton made
of calcium carbonate.
D
Digestive system: The long tubes that break
down your food and take it into your blood,
and the organs that go with it.
Dredging: To remove or recover material from
under water by means of a dredge.
E
Electrical conductor: Materials through which
electric current can pass.
Electrical insulator
insulator: Materials through which
electric current cannot pass.
Electricity: Energy created by moving charged
particles.
Element: A substance made of only one kind of atom.
Embryo: A plant in its earliest stages of development.
In see bearing plants, the embryo is contained
within the seed.
Endangered: A plant or animal is said to be
endangered when it is in danger of becoming
extinct.
Energy: The ability to do work, this has many different
forms, eg. Heat, sound, light.
Estimat
e: To make an approximate calculation of
Estimate:
something.
Extinct: A species that has died out has become
extinct.
F
F a t : A type of food and a store of energy in
animals and plants.
Fission: A type of asexual reproduction found in
corals where the parent polyp splits into two
new polyps.
Fossil fuel: Fuel that formed over millions of years
from the remains of living things
Force: A push or a pull, measured in newtons (N).
Freq
uency: The number of vibrations in each
requency:
second. A sound with a high frequency has a
high pitch.
Friction: A force which slows down movement.
G
Gill: The organ that fish and some other aquatic
animals use to breathe, consisting of a
membrane containing many blood vessels
through which oxygen passes.
Global warming: The warming of the Earth due to
the greenhouse effect.
Glucose: A simple sugar produced in plants by
photosynthesis and in animals by the
conversion of carbohydrates, proteins and fats.
Green house effect: The trapping of heat from
the Sun in the Earth’s atmosphere by green
house gases such as carbon dioxide and
oxides of nitrogen, causing global warming.
H
Heat conductor
conductor::Materials which heat can pass
through.
Heat insulator:
insulator:Materials which heat cannot pass
through.
I
Indicator: A chemical that is one colour in a alkali
and a different colour in an acid.
J
Joule: A measurement of energy.
L
Lever: An easy way of lifting heavy weights
Litmus: An indicator that is red in acids and blue in
alkalis.
Lung: The paired respiratory organ situated inside
the ribcage in animals that transfer oxygen
into the blood and remove carbon dioxide
from it.
M
Mass: The amount of matter in an object or an
animal. Mass is measured in kilograms.
Minerals: An inorganic substance that must be
ingested by animals or plants in order to
remain healthy.
Mixture: Different types of atoms and molecules
which are not joined together chemically and
so can easily be separated.
Multicellular organisms: An organism with more
than one cell.
N
Neutral: A substance that is neither acidic nor
alkaline is neutral.
Neutralization: A chemical reaction between an
acid and a base that produces a neutral
solution.
Non-renewable: Energy sources that are used up
are non-renewable, e.g. fossil fuels.
O
Organ: A group of different tissues working
together to carry out one or more bodily
functions. E.g. stomach and heart
Oxides of nitrogen: Poisonous gaseous
compounds containing oxygen and nitrogen.
Dissolve in rain water o form acid rain.
Ozone layer: A layer of ozone gas in the
atmosphere. It protects us from the harmful
ultraviolet rays of the Sun by absorbing most
of it.
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P
S
Parallel circuit: A circuit in which two or more
components are wired side by side
Peristalsis
Peristalsis: The muscles of the gut squeeze the
food along by contracting in waves
pH scale: Scale of numbers from 1 (strongest
acid) through 7 (neutral) to 14 (strongest
alkali).
Photosynthesis: The process plants use to make
food.
Pitch: How high or low a sound is.
Pivot : The point around which a lever turns
Plumule: Primary shoot of a plant embryo.
Pollutants: Something that pollutes, for example,
chemicals or waste products that contaminate
the air, soil or water.
Pollution: The act of polluting something,
especially the natural environment.
Posture: The way in which somebody carries his or
her body, especially when standing.
R
Radiation: Any kind of energy that is emitted from
a source in the form of rays or waves, for
example, heat, light or sound.
Radicle: The part of a plant embryo that forms the
root of the young plant.
Reflection : The process or act of reflecting
something, especially light, sound or heat.
Renewable: Energy sources that can be replaced
are renewable, e.g. wood, solar power.
Resistance: The opposition that a circuit component
or substance presents to the flow of electricity.
Natural Resources: A naturally occurring material
such as coal or wood that can be exploited by
people.
Respiration: A chemical reaction that happens in
your cells to release energy. The reaction uses
oxygen and glucose, and produces water and
carbon dioxide.
Respiratory system Your lungs and the tubes
connecting them to your nose and mouth. Your
respiratory system is used for gas exchange.
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Seed: Plant part containing embryo.
Series circuit: A circuit in which two or more
components are wired end to end.
Sound energy: Energy in the form of sound.
Stamina: Enduring physical or mental energy and
strength that allows somebody to do
something for a long time.
Starch: A carbohydrate substance manufactured
by plants and stored in seeds.
S t o m a t a : A tiny pore in the outer layer of a plant
leaf or stem that controls passing of water
vapour and other gases into and out of the
plant.
Streamlined: Shaped to make the effect of
friction less.
Strength: The physical or mental power that
makes somebody or something strong.
T
Thermometer: An instrument for measuring
temperature.
Threatened: Used to describe an organism or
species that is in danger of becoming extinct.
Tissues: Number of cells join together to form
tissues.
U
Universal indicator: An indicator that has a
range of colours showing the strength of an
acid or alkali on the pH scale.
V
Vibrate: Make regular shaking movements, which
are sometimes too small to see. Sounds are
made by vibrations.
Vitamins: Organic substances essential in small
small quantities to the nutrition and normal
metabolism of most animals.
Z
Zooxanthellae: A microscopic yellow-green algae
that lives within the cells of corals.