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 – national, state, provincial, or local parks.

A bacterium, virus, or other microorganism that can cause disease

Disease-causing microorganisms.

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 – 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

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.

 UK:  The prescribed syllabus that pupils must be taught ateach key stage in the National Curriculum