OCR GCSE Bio definitions Paper 4

Ecosystem

All the living organisms and physical conditions in an area.

Community

All the living organisms within an ecosystem.

Habitat

The area in which animals in an ecosystem live in.

Population

The total number of organisms of any one species.

Biomass

The entire mass of living material present.

Decomposers

Organisms that gain energy by feeding on dead material.

Interdependence

How organisms depend on each other within a community.

Predation

Relationship between a predator and a prey.

Mutualism

Relationship where both organisms benefit.

Parasitism

Relationship where only one organism benefits.

Decomposition

The process by which dead plants and animals break down into simpler substances.

Variation

Differences within a species.

Discontinuous variation

Characteristics that fall into distinct groups.

Continuous variation

Characteristics that are values between a range.

Clone

A genetically identical organism produced from a single parent.

Mutation

A change in the sequence of DNA bases.

Natural selection

The process in which organisms with advantageous traits survive and reproduce.

Classification

The process of sorting living organisms into groups.

Sample

A measurement of a small area that is representative of a larger area.

Gene

A section of DNA that carries the instructions for a specific characteristic.

Allele

A different version of a gene.

Phenotype

Outward expression of an organism.

Genotype

Inward expression of an organism.

Biodiversity

The variety of living organisms present in an area.

Ecotourism

Aims to ensure that tourism does not have a negative impact on the natural environment.

Conservation

Protecting a natural environment to ensure that habitats are not lost.

Captive breeding

Breeding animals in a human-controlled environment (before releasing them back in the wild).

Indicator species

Organisms that can be used to measure environmental quality.

Food security

The ability of human populations to access affordable food of sufficient quality and quantity.

Sustainable food production

Producing food in ways that can be continued indefinitely.

Biological control

The use of living organisms to control pest populations.

Hydroponics

A method of growing plants in water containing dissolved minerals.

Genetic engineering

Process of changing an organism’s DNA to produce an organism with desired characteristics.

Sticky ends

Exposed unpaired bases on the ends of DNA strands.

Biotechnology

The use of biological processes or living organisms to manufacture products.

Disease

A condition caused by a part of the body not functioning properly.

Monoclonal antibodies

Identical antibodies that are designed to target a specific cell (produced by a single clone of cells).

Vaccine

A substance containing small amounts of weakened/dead pathogens.

Aseptic technique

An approach to working which prevents cross-contamination from unwanted microorganisms.

Cardiovascular disease

A disease of the heart or blood vessels.

Gene therapy

The placement of a fully functioning allele into a cell containing a faulty allele for the same gene.