populations in ecosystems Flashcards
Define habitat
The place where an organism lives
Define population
All the organisms of one species in a habitat
Define community
Populations of different species in a habitat
Define ecosystem
A community, plus all the abiotic conditions in the area in which it lives
Define abiotic conditions
The non-living features of the ecosystem
Define biotic conditions
The living features of the ecosystem
Define niche
The role of a species within its habitat
Define adaptation
A feature that members of a species have that increases their chance of survival and reproduction
What does a niche include?
- Biotic interactions e.g. the organism it eats or is eaten by
- Abiotic interactions e.g. the oxygen an organism breathes in, and the carbon dioxide it breaths out
How many species are in a niche
One
What are niches separated by
- Time
- Location
- Behaviour
Why are niches important?
To avoid inter-species competition
Why are ecosystems described as being dynamic?
- Populations constantly rise and fall
- Any small change can have a large effect
- Biotic and abiotic factors may alter the conditions of the ecosystem
What are the 3 different types of adaptations?
- Physiological
- Behavioural
- Anatomical
Describe how adaptations become more common in the population
- Organisms with better adaptations are more likely to survive, reproduce and pass on alleles for their adaptation
- So the adaptation becomes more common in a population
Define population size
The total number of organisms of one species in a habitat
Define the carrying capacity
The maximum stable population size of a species that an ecosystem can support
List abiotic factors which may affect population size
- Amount of light, water and space available
- Temperature
- Chemical composition of their surroundings
What resources might organisms compete for?
- Food
- Water
- Shelter
- Minerals
- Light
- Mates