Page 46 - ICC Science Dictionary (spreads)

Word Definition Topic(s) Word Definition Topic(s)

opaque Not transparent or see-through. C10, P6 oscillations The repeated and regular fluctuations, P6
above and below the same position,
operculum A flap on the side of the head of B2 eg the pressure of a sound wave or
a fish through which water passes the voltage of an alternating current.
after it has flowed over the gills.
oscilloscope Device for viewing patterns, for TP2, P6
optimum The best or most appropriate - for B2, B7a, B7b example of sound waves that have
instance, the conditions under been turned into electrical current.
which an enzyme works best (eg
temperature and pH). osmoregula- A form of homeostasis which controls B5
tion the volume of water in the body.
orbit Curved path taken by a satellite, TP5
planet or star moving around a osmosis The movement of water molecules B1a, B1b, B2,
larger body. Earth completes one across a selectively permeable B5, C10
orbit of the Sun every year. membrane from a region of higher
water concentration to a region of
order of A number, to the base ten, often B1a, B1b, C2 lower water concentration.
magnitude used to make comparisons. For
each order of magnitude, a number outer core The Earth's outer core is a fluid layer P6
is ten times the previous one. that sits above the solid inner core.
ore Naturally occurring rock, from TC4, C4, C10 output force The force that is applied to the TP4
which metal can be obtained. object moved by the machine.
organ A group of different tissues that work TB1,B2, B4 ovary Organ which contains eggs. TB3
together to carry out a particular overfishing To catch fish in such high numbers B7a, B7b
function, eg heart and lungs. that species struggle to survive.
organic Compounds that contain carbon C7 oviduct, or Carries an egg from the ovary to TB3
compound atoms, joined by covalent bonds fallopian the uterus and is where fertilisation
to other atoms (including other tube occurs.
carbon atoms).
ovulation Release of an egg cell during the TB3
organic When crops are grown without the B7a, B7b menstrual cycle, which may be
farming use of chemicals. met by a sperm.

organism Living entity, eg animals, plants or B1a, B1b, B2, ovules Female sex cells in plants found in TB2
microorganisms. B3, B6, C7, C9, the ovary.
C10
oxidation The gain of oxygen, or loss of C4, C5, C9
oscillation Vibration P6 electrons, by a substance during a
chemical reaction.