Topic B7 - ECOLOGY Flashcards
Population definition
All the organisms of one species living in a habitat.
Community definition
Populations of different species living in a habitat
Stable Community
All species and environmental factors are in balance, population sizes are roughly constant
Ecosystem
Interaction of a community of organisms and the parts of their environment that are non-living
Adaptation
Enables an organism to survive in the conditions of its normal habitat
Interdependence
Each species in a community depending upon other species for things, e.g pollination, food, or shelter
What does biotic factors mean?
Biotic means living factors
What does abiotic factors mean?
Non-living factors
What two types of factors can affect organisms in a community?
Both biotic (living) and abiotic (non-living)
What factors can affect organisms in a communtiy?
1) light intensity - abiotic
2) wind intenisty and direction - abiotic
3) moisture level - abiotic
4) competition - biotic
5) CO2 level for plants - abiotic
6) New predators - biotic
7) food availability - biotic
8) temperature - abiotic
9) solid pH and mineral content -abiotic
10) new pathogens - biotic
11) O2 level for aquatic animals -abiotic
What do organisms conpete for?
Plants: ~ light ~ space ~ minerals ~ water
Animals:
~ food
~ mates
~ territory
How can a change in an ecosystem affect the community?
Due to interdependence, change in an ecosystem (e.g. a species being removed) can affect the whole community.
What is the order of food chains?
Producer ~> Primary Consumer ~> Secondary Consumer ~> Tertiary Consumer
Producer
A plant or alga that makes glucose by photosynthesis. All food chains start with a producer.
Primary Consumer
An animal that eats producers and may be eaten by secondary consumers.
Secondary Consumers
An animal that eats primary consumers and may be eaten by tertiary consumers.
Predator
A consumer that kills and eats other animals (prey)
Biomass
The mass of a living material
What do arrows represent in food chain?
Energy transfer,
Energy stored in biomass is transferred along food chains and used by other organisms to build biomass.
What is a sign of a stable community?
In a stable community the numbers of predators and prey rise and fall in cycles.
The Predator-Prey Cycle
~ Prey Population Increases
~ Predator Population Increases
~ Prey Population Decreases
~ Predator Population Decreases
^^^ REPEATS IN CYCLE ^^^
Why are Predator-Prey Cycles always out of phase with each other?
Because it takes a while for one population to respond to changed in the other population.
Biodiversity
The variety of different species on Earth, or within an ecosystem.
High Biodiversity
~ Lots of differnet species
~ Reduced dependence of one species on another for things like food, shelter and the maintenance of the physical
environment
= Stable Ecosystems