Ecology Flashcards
What is an ecosystem?
A system or area where organisms interact with their physical environment
What two things do all ecosystems have?
Biotic factors (Living things) Abiotic factors (non-living things)
What three general groups of things are BIOTIC?
Producers (e.g Photosynthesising plants), Consumers (e.g animals), Decomposers (Breakdown organic matter)
Define ABIOTIC?
A physical environment that affects the growth and survival of living things
What is the variety of species found within an ecosystem called?
Biodiversity
An ecosystem contain a range of…
Habitats
What is one way to measure the size of a population in a habitat?
Use a quadrat
To find out the population of a species in a habitat what would you do? (Clue: State the method)
- Calculate area of habitat
- Measure number of individuals in one quadrat and repeat 3 times
- Calculate average number of individuals in quadrat
- Calculate how many quadrants fit into the total area
- Multiply the result from step4 by the result from step 3
What is random sampling?
It makes our data valid as it avoids choosing areas which may be interesting which would bias our results
How do you take a random sample?
- Lay out two tape measures a right angles to make a 10m by 10m axis
- Generate a random pair of numbers between 1 and 10
- Use these as coordinates to place your quadrat
How do you measure a population? (Clue: Quadrats)
- Count the number of individuals of the chosen species in the square
What is a community?
The populations of all the species present in an ecosystem at a particular time
In what three ways do species in a community interact with each other and the physical environment?
- Feeding on each other
- Competition for resources (e.g food, mates, nesting sights)
- Using abiotic resources (e.g absorbing mineral ion from the soil)
What do arrows mean in a food chain?
“Is eaten by”
What are the stages in a food chain called?
Trophic levels
State all the trophic levels of the food chain?
Producers, Primary consumer, Secondary consumer, Tertiary consumer
What is important about an Ecological pyramid?
They are always drawn to scale
How much energy is passed from one trophies level to another?
10% of energy is passed from one trophies level to another
Why is only 10% of energy passed from one trophies level level to another?
- Some parts of the organism are not eaten
- Some parts are not digested and absorbed (egested as faeces)
- Some materials are respired to release energy (matter is lost as CO2 and Water)
