Expansion or development of land to the point of damage
Fishing with a sufficiently high intensity to reduce the breeding stock levels to such an extent that they will no longer suppport a sufficient quantity of fish for sport or commercial harvest
A naturally occurring, highly reactive gas comprising triatomic oxygen formed by recombination of oxygen in the presence of ultraviolet radiation.
The reduction of the protective layer of ozone in the upper atmosphere by chemical pollution.
A hole or gap in the protective layer of ozone in the upper atmosphere.
Drugs or medicines for relieving pain
An epidemic of infectious disease that has spread through human populations across a large region; for instance multiple continents, or even worldwide. (plural : Pandemics)
People entrusted with protecting and preserving parklands â€“ national, state, provincial, or local parks.
A bacterium, virus, or other microorganism that can cause disease
the orientation of a plant or other organism in response to light, either towards the source of light ( positive phototropism ) or away from it ( negative phototropism )
the branch of science concerned with the nature and properties of matter and energy. The subject matter of physics includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms.
The major endocrine gland, a pea-sized body attached to the base of the brain that is important in controlling growth and development and the functioning of the other endocrine glands
A placebo is a dummy pill or injection given to members of a control
group in medical trials. Where a placebo is in the form of a pill, it
should be identical to the pill used with the experimental group. The
only difference should be that that the placebo does not contain the
drug being trialled. The use of placebos helps to ensure that the
data collected from a trial are valid.
A contaminant that adversely alters the physical, chemical, or biological properties of the environment
The presence in or introduction into the environment of a substance which has harmful or poisonous effects.
Precise measurements are ones in which there is very little spread about the mean value.
Precision depends only on the extent of random errors â€“ it gives no indication of how close results are to the true value.
A prediction is a statement suggesting what will happen in the future, based on observation, experience or a hypothesis
Principle of Superposition
The Principle Of Superposition states that when two waves of the same kind meet at a point in space, the resultant displacement at that point is the vector sum of the displacements that the two waves would separately produce at that point.
Probability is the likelihood of an event occurring. It differs from
chance in that it can be expressed mathematically. In statistical
tests, probabilities are usually expressed as a decimal fraction of
one. Thus a probability of 0.01 means that an event is likely to occur
1 time in every 100.
A steroid hormone released by the corpus luteum of the ovary that stimulates the uterus to prepare for pregnancy.
Programme of study
UK: The prescribed syllabus that pupils must be taught ateach key stage in the National Curriculum
questioning or a short test
These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next. Random errors are present when any measurement is made, and cannot be corrected. The effect of random errors can be reduced by making more measurements and calculating a new mean.
The maximum and minimum values of the independent or dependent variables.
For example a range of forces may be quoted as either:
"From 0 N to 20 N" or "From 20 N to 0 N"
Organs or cells able to respond to light, heat, or other external stimuli and transmit signals to sensory nerves.
A measurement is repeatable if the original experimenter repeats the investigation using same method and equipment and obtains the same results
A measurement is reproducible if the investigation is repeated by another person,
or by using different equipment or techniques, and the same results are obtained.
This is the smallest change in the quantity being measured (input) of a measuring instrument that gives a perceptible change in the reading
A process which estimates the likelihood that exposed people may have health effects. The four steps of a risk assessment are: hazard identification (Can this substance damage health?); dose-response assessment (What dose causes what effect?); exposure assessment (How and how much do people contact it?); and risk characterization (combining the other three steps to characterize risk and describe the limitations and uncertainties).