1.1. Populations and ecosystems Flashcards
Define Ecology
The study of the biosphere, and of interrelationships between organisms and their environment.
Define Biosphere
The life-supporting layer of land, air and water that surrounds the Earth.
Define Abiotic factor
An ecological factor that makes up part of the non-living/non-biological environment of an organism.
Define Biotic factor
An ecological factor that makes up part of the living/biological environment of an organism.
Define Ecosystem
A more or less self-contained functional unit in ecology made up of all the interacting biotic and abiotic factors in a specific area.
2 major processes within ecosystems?
- Flow of energy through ecosystem
- Cycling of elements within ecosystem
Ecosystem made up of?
Many different species
Define Species
A group of genetically similar organisms that can breed to produce fertile offspring.
Species made up of?
Many populations
Define Population
A group of interbreeding organisms of the same species that occupy the same habitat at the same time.
Why are boundaries of a population difficult to define? (2)
- In theory - any 2 members of the same species can interbreed
- In practise - long distance makes interbreeding unlikely, considered separate populations
Populations of different species form?
A community
Define Community
All the populations of different organisms living and interacting in a particular place at the same time.
Define Habitat
The place where an organism normally lives, which is characterised by physical conditions, and the species of other organisms present.
Define Microhabitat
A smaller unit within a habitat, each with its own microclimate.
Define Ecological niche
All conditions and resources required for an organism to survive, reproduce and maintain a viable population.
No 2 species occupy…
Due to differences in? (4)
…exactly the same niche
- Behaviour - nesting habits
- Tolerance of environmental factors - pollution/shortage of O2 or N2
EXAM QUESTION
Ecologists studies a community of fish in a lake.
Explain what is meant by a community.
All the fish/all the species/all the
populations/all the organisms;
EXAM QUESTION
The ecologists found that each species of fish had adaptations to its niche. One of these adaptations was the shape of its mouth.
Suggest how the shape of mouth is an adaptation to its niche.
1. With different mouth eats different food / has different way of feeding / specific mouth shape for specific food; 2. Competition between species/interspecific competition is reduced;
EXAM QUESTION
The position of the tree line is determined by abiotic factors.
What is meant by an abiotic factor?
Non-living/physical/chemical
factor/non biological;