Combined Science key terms

An approximate value based on observations or measurements, used when an exact value is unnecessary or cannot be obtained reliably.

The alcohol produced by anaerobic respiration in plant and yeast cells.

A question about whether an action and its consequences are right or wrong.

An organism whose cells contain a nucleus.

A cell whose genetic material is enclosed within a nucleus. Plant and animal cells are eukaryotic cells.

Nutrient enrichment of water that causes excessive algal growth, followed by death and decomposition of plants and a decrease in dissolved oxygen.

The change of state from liquid to gas.

A change in the inherited characteristics of a population over time through natural selection.

A branching diagram showing scientists’ understanding of evolutionary relationships between organisms.

More reactant than is needed to react completely with the other reactant, so some remains unreacted.

A reactant supplied in more than the amount needed to react completely with the other reactant, so some remains when the reaction finishes.

A specialised surface across which substances move between an organism and its environment, or between body compartments.

A change or reaction in which heat energy is given out to the surroundings.

A chemical reaction that transfers energy to its surroundings.

The increase in an object’s length compared with its unstretched length, measured in metres (m).

The permanent loss of a species when all its members have died.

An organism adapted to live in extreme conditions, such as very high temperature, pressure or salt concentration.

A diagram tracing the inheritance of a characteristic through generations of a family.

A diagram showing relationships between individuals and the inheritance of a characteristic across generations; also called a pedigree.

A raw material used as the starting material for an industrial process.

Anaerobic respiration in yeast cells, which produces ethanol and carbon dioxide from glucose.

Offspring that can themselves reproduce.

The fusion of male and female gamete nuclei, combining their chromosome sets to form a zygote.

A substance added to soil to supply mineral nutrients needed for plant growth.

A region in which an object experiences a force because of its mass, electric charge or magnetic properties.

A strip at the edge of a crop field where plants such as wild flowers and grasses are allowed to grow.

The area of the specimen visible through a microscope at one time.