U3T2 - Ecosystems | Monty Flashcards
To be able to handle to fern.
What are autotrophs?
Organisms that convert inorganic substances into organic matter.
How do photoautotrophs produce their own food?
Photosynthesis:
Sunlight + CO₂ + Water => C₆H₁₂O₆ (Glucose) + O₂
How do chemoautotrophs produce their own food?
Chemosynthesis:
Oxidization of inorganic chemicals for energy.
What are heterotrophs?
Organisms that obtain energy from autotrophs and other heterotrophs.
How do heterotrophs obtain energy?
By converting glucose into ATP.
How is biomass created?
Organic material and energy is stored in organisms.
How is energy lost through photosynthesis?
95 - 99% of energy is lost through:
- Reflection
- Radiation
- Absorption
What is the difference between Gross Primary Productivity and Net Primary Productivity?
GPP:
Rate at which solar energy is used to fix carbon into organic molecules.
NPP:
Excludes energy used for metabolism.
What is a trophic level?
An organism’s level in the food chain of an ecosystem based on feeding relationships.
How much and in what ways is energy lost between trophic levels?
90% of energy is lost:
- 80% in metabolism (heat)
- 10% in biological waste
What does a biomass pyramid show?
The amount of biomass stored in each trophic level of an ecosystem.
The stability of an ecosystem:
- If an ecosystem does not have consistently decreasing trophic level mass, it is unstable.
Briefly describe the six stages of the water cycle:
- Evaporation: Water heats and rises as vapor.
- Condensation: Water vapor become clouds.
- Precipitation: Clouds condense and fall (rain).
- Transpiration: Water vapor rises from leaf stomata.
- Respiration: Animals’ breathing releases water vapor.
- Run-off: Land water drains to rivers.
What is biogeochemical cycling and how does it work?
Process of cycling nutrients through ecosystems.
Chemicals are:
- Absorbed / transformed by living organisms.
- Moved through trophic levels.
- Decomposed into abiotic environment.
What are the five ways carbon enters an ecosystem?
- Combustion of fossil fuels
- Respiration of organisms
- Decay of biotic organisms
- Evaporation from water
- Volcanic activity
Where is carbon stored in an ecosystem?
- Photosynthesis in plants
- Dissolving in water
- Formation of fossil fuels
- Stored as biomass
How does atmospheric carbon dioxide affect the surrounding environment?
- Changes in weather
- Insulates Earth’s atmosphere
- Reflects sunlight
What are the five ways nitrogen enters the soil?
- Denitrification: Decay of living organisms returns nitrogen as ammonia
- Ammonification: Bacteria in soil & legumes fix nitrogen into ammonia
- Nitrification: Soil bacteria convert ammonia into nitrite & nitrate ions.
- Lightning forms nitrogen dioxide which dissolves in rain to form nitrate ions.
- Fertilizers contain nitrogen compounds.
How does nitrogen exit the soil?
- Plants take up nitrogen to produce proteins, which are then consumed by animals.
What is a niche?
Role an organism fills in an ecosystem, including all biotic and abiotic interactions.
How the organism uses the resources available in its habitat.
What does the competitive exclusion principle define?
- Two species requiring same resources can occupy same habitat but not same niche.
- Species can only coexist if they have different requirements.
What is a keystone species?
A species that heavily impacts their ecosystem, and is critical for maintaining the structure and stability of the ecosytsem.
What is carrying capacity?
Size of population that can live indefinitely with available resources of ecosystem.
What is a limiting factor?
A biotic or abiotic factor of an ecosystem that limits the size of a population.
What are examples of biotic limiting factors?
- Competition
- Predation
- Disease
- Parasites
