Populations Flashcards
Habitat
Place where an organism lives
Population
All the organisms of one species in a habitat
Community
Populations of different species in a habitat make up a community
Ecosystem
All the organisms living in a particular area and all the abiotic conditions (eg. Lake)
Abiotic conditions
Non-living features of an ecosystem (eg. Temperature)
Biotic conditions
Living features of an ecosystem (eg. Predators)
Niche
Role of a species within a habitat (eg. Its diet)
Adaptation
A feature that members of a species have that increases their chance of survival and reproduction
How are organisms adapted to abiotic and biotic conditions?
Physiologically, behaviourally and anatomically.
What do better adaptations mean for a species?
They are more likely to survive, reproduce and pass on alleles, meaning adaptions become more common in the population - natural selection.
Every species is adapted to use an ecosystem in a way that no other species can.
Abundance
Number of individuals of one species in a particular area.
Distribution
Where a particular species is within the area investigated.
Equation of Mark-Release-Recapture
(Number caught in first sample x number caught in second sample) all over the number marked in the second sample.
Three assumptions of Mark-Release-Recapture:
I - marked sample has had enough time and opportunity to mix back in with the population.
II - marking hasn’t affected its chance of survival and is still visible.
III - changes of population size is small during the study period, ie. birth, death, migration.
Which biotic factors cause variation in population size?
Interspecific competition, intraspecific competition and predation.
