B7 - Ecology Flashcards
(20 cards)
What is an ecosystem?
A community of living organisms (biotic) interacting with the non-living (abiotic) parts of their environment.
Define interdependence.
When organisms in an ecosystem rely on each other for resources like food, shelter, pollination, and seed dispersal.
What are abiotic factors? Give two examples.
Non-living factors affecting organisms, e.g., temperature and light intensity.
What are biotic factors? Give two examples.
Living factors affecting organisms, e.g., availability of food and presence of predators.
What is a stable community?
A community where environmental conditions and population sizes remain relatively constant over time.
What is the difference between a producer and a consumer in a food chain?
Producers make their own food (usually plants); consumers eat other organisms for energy.
How is energy lost at each trophic level in a food chain?
Through respiration, movement, heat loss, and undigested materials.
Explain the role of decomposers in an ecosystem.
They break down dead organisms and waste, returning nutrients to the soil.
Describe the carbon cycle in terms of photosynthesis and respiration.
Photosynthesis removes CO₂; respiration by plants, animals, and decomposers releases CO₂.
What human activities increase the level of carbon dioxide in the atmosphere?
Burning fossil fuels and deforestation.
Why is biodiversity important?
It increases ecosystem stability by reducing dependency on one species.
Name three ways humans reduce biodiversity.
Deforestation, pollution, and overexploitation (e.g., hunting, fishing).
What is global warming, and how does it affect ecosystems?
The gradual increase in Earth’s temperature due to greenhouse gases; it can alter habitats and lead to species extinction.
What are indicator species? Give one example.
Organisms used to monitor pollution levels, e.g., lichens indicate air quality.
Explain how the water cycle supports life on Earth.
It recycles water through evaporation, condensation, and precipitation, making it available for organisms.
What is meant by ‘trophic level’?
The position an organism occupies in a food chain or web.
How can food security be threatened?
By population growth, climate change, pests, and loss of pollinators.
What is biomass?
The mass of living material in an organism, often measured as dry mass.
What is a quadrat used for?
To estimate the population size or distribution of organisms in a given area.
What conservation strategies help protect biodiversity?
Breeding programs, habitat protection, seed banks, and legislation to reduce deforestation and pollution.
