Life processes in the biosphere Flashcards
Taxonomy
The study of organisms to assess how they can be grouped or classified
Ecological succession
The sequence of changes in community composition as an area is colonised and develops to become the climax community. 5 stages - nudation (bare land), invasion, competition, coaction, reaction, climax. eg. After a forest fire, grasses might grow, then shrubs, then trees until there is a mature forest.
Community
All the populations of all the species living in an area.
Carrying capacity
The greatest population that can be supported sustainably in an area.
Biome
A large geographical region with particular climatic features and a characteristic, unique community of species.
Density independent factor
Also known as a limiting factor. Any force that influences the size of a population of living things regardless of population density eg earthquake - it will kill all members of a population, whether the population is large or small. Also could be food limitation, pollutants, climate extremes eg monsoon
Autotroph
An organism that gains its energy from light or chemical reactions, not by eating other organisms. They can produce their own food. eg plants
Sometimes called producers.
Density dependent factor
Any force that affects the size of a population of living things in response to the density of the population eg disease (spreads faster in areas where individuals live in close proximity). Also competition for food, water, nesting sites.
Edaphic
Factors relating to the soil. Eg. soil texture, ph level, aeration, mineral levels etc.
Pollination
The transfer of male gametes (pollen) onto the female part of a flower, followed by fertilisation
Ecosystem
A community of organisms, their inter relationships and interactions with the abiotic environment
Genus
A group of closely related species. It’s a taxonomic group covering more than one species.
Heterotroph
An organism that gets its food energy from other organisms eg animals, fungi, bacteria. It eats other plants or animals for energy and nutrients.
Population
All the individuals of a species living in a particular area
Habitat
The place where an organism, species or population lives.