Ecology Flashcards
Define population
A group of organisms of the same species who live in the same area at the same time
Define autotroph
Organism which produces carbon compounds for consumption
Define heterotroph
Organism which consume carbon compounds by eating other organisms
Define detritivore
Organism which obtains organic nutrients by internal digestion of waste products
Define saprotroph
Plant which obtains nutrients from dead organic matter by external digestion
Define community
Interacting populations occupying a given area, upon which they depend on its abiotic environment
What does an ecosystem include
- abiotic environment
- a community
- interactions in communities and between organisms and abiotic environment
What do ecosystems need to be sustainable?
- A nutrient cycle to maintain the supply of inorganic matter for organisms to survive
- Detoxification of waste products
- Energy availability
What is the main source of energy for most living organisms?
The sun.
Define food chain.
A sequence of organisms, each of which feeds on the previous one
Define trophic level.
The level of heterotroph in the food chain sequence.
How does energy flow in food chains? How does this limit the length of food chains?
- Chemical energy in carbon compounds flows through food chains through feeding. Energy released by respiration is used in living organisms and converted to heat, which is released into the abiotic environment
- 90% of energy at each trophic level is lost due to usage or as heat. Each trophic level requires 10x as much energy to begin with to exist.
Define carbon fixation.
The conversion of CO2 to organic compounds by living organisms.
How is peat formed?
Peat forms when organic matter is not fully decomposed because of anaerobic conditions in waterlogged soils.
- Water fails to drain out of soil, making it waterlogged and anaerobic
- saprotrophs can’t thrive in this so dead organic matter isn’t fully decomposed
- increased acidity inhibits saprotrophs and methanol ends developing
- partially decomposed matter accumulates, compresses and forms a brown acidic material called peat
Explain the creation of coal. Explain the creation of oil.
- Peat is buried under other sediments. Peat is thus compressed and heated into coal.
- Mud at the bottom of seas, lakes not fully decomposed due to anaerobic environment. Matter compressed and heated as more sediment is added on. Becomes oil over time.
