Ecology and Nutrient Cycles Flashcards
Define community
All the different species in a habitat
Define ecosystem
All the organisms living in a particular area and all the non-living (abiotic) conditions
Define habitat
The place where an organism lives
How would you decide to place your quadrat when doing an experiment?
- choose places randomly
- make a grid in field and assign each square a number
- roll a dice to decide
Define population
A group of organisms of one species, living in the same area at the same time
Describe an experiment to estimate population size of a species in different areas using a quadrat
1) place a 1m squared quadrat on the ground at a random point within the area you’re investigating
2) count all the organisms within the quadrat
3) use the quadrat at several other points to get an average value for organisms in the quadrat, then multiply that by the total area (in m squared)
What are the trophic levels?
Tertiary consumer
Secondary consumer
Primary consumer
Producer
How does the producer make their own food?
Using energy from the Sun in photosynthesis
What is a decomposer?
An organism, such as bacteria or fungi, which break down (decompose) dead material and waste
Why is only about 10% of energy transferred from one trophic level to the next?
A lot of energy is lost in various ways:
- respiration
- maintaining constant body temperature
- some parts aren’t eaten by organisms (roots or bones) so the energy isn’t taken in
- some parts are indigestible (fibre) so pass through the organisms and come out as waste (faeces)
All species in a food web are …………………….., meaning if one species change, it affects all the others.
Interdependent
What do the arrows in a food web show?
The direction of the flow of energy through the ecosystem
