A2 Biology Unit 4 Definitions Flashcards
To learn the definitions by rote.
Eco-System
A self-contained unit made up of all the biotic and abiotic features in a specific area.
Population
A group of interbreeding organisms of one species in a particular habitat.
Community
All the populations of different organisms living and interacting in a particular place at the same time.
Habitat
The place where a community of organisms lives.
Niche
How an organism fits into an environment, referring to where it lives and what it does there.
Abundance
The number of individuals in a species in a given place.
Frequency
The likelihood of a particular species occurring within a quadrat.
Percentage cover
An estimate of an area within a quadrat that a particular plant species covers.
Biotic
The living part of the environment.
Abiotic
The non-living part of the environment.
Intra-specific
Within a particular species (when referring to competition).
Inter-specific
Between two or more different species (when referring to competition).
Predator
An organism that feeds on another organism.
Prey
An organism that is consumed by another organism.
Ecology
The study of inter-relationships between organisms and their environment.
Biosphere
The layer of land, air and water that surrounds the Earth.
Producer
Photosynthetic organisms that manufacture organic molecules using light energy, water and carbon dioxide.
Consumer
Organisms that obtain energy by feeding on other organisms.
Primary consumer
Organisms that obtain energy by feeding on producers.
Secondary consumer
Organisms that obtain energy by feeding on primary consumers.
Decomposers
Micro-organisms e.g. bacteria and fungi, that break down complex organic molecules into simple components and release minerals and elements into the soil.
Detritivore
Small organisms e.g. woodlice and earthworms, that break down the complex organic molecules in dead and decaying plant and animal matter.
Saprobiotes
Organisms that break down dead and decaying matter by secreting enzymes and then digesting it.
Food chain
A feeding relationship in which the producers are eaten by primary consumers, which in turn are eaten by secondary consumers.
Trophic level
The position of an organism within a food chain.
Gross production
Total quantity of energy that the plants in a community convert to organic matter.
Net production
The rate at which plants can store energy from the sun.
Biomass
Total mass of plants and/or animals in a particular place.
Dry biomass
Total mass of plants and/or animals in a particular place, minus their water content.
