SB9 Flashcards
What is an ecosystem?
All the organisms and the environment they live in.
What is a population?
A group of the same species that live in a particular area.
What is a habitat?
The area in which an organism or population lives.
What is a community?
All the different organisms that live in a particular area.
What does interdependent mean?
When two organisms are dependant upon each other.
What are producers?
Organisms that use sunlight energy to produce food.
What are consumers?
Organisms that get their energy by eating other organism (producers/consumers).
What is a primary consumer?
Gets it energy by eating plants.
What is a secondary consumer?
Gets its energy by eating primary consumers.
What is a tertiary consumer?
Gets its energy by eating secondary consumers.
What abiotic factors affect communities?
Temperature
Amount of water
Light intensity
Levels of pollution
What biotic factors affect communities?
Competitions - organisms compete with other species for the same resources.
Predators - e.g - number of lions decrease = gazelles might increase.
What is a quadrat?
Its a square frame enclosing a know area.
What do pyramids of biomass show?
Weight
What’s the equation for efficiency?
Energy transferred to next level/energy available at previous level x 100
What is eutrophication?
An excess of nutrients in water.
It can lead to death
From fertilisers - if too much is applied and rains afterwards
What is a non-indigenous specie?
Its one that doesn’t naturally occur in an area.
Can cause problems with indigenous species - more competition, disease.
How do we conserve and maintain biodiversity?
Reforestation
Conservation schemes
What are the benefits of maintaining biodiversity?
Protecting human food supply Ensuring minimal damage to food chains Providing future medicines Cultural aspects Ecotourism Providing new jobs
What does reforestation do?
Can increase biodiversity in deforested areas.
What do conservation schemes do?
Protect at risk species from dying out.
Protecting a species natural habitat.
Protecting species in safe areas outside their habitat.
The use of seed banks.
What are biological factors affecting the level of food security?
Increasing human population.
Increasing consumption of meat, fish and increasing animal farming.
Environmental changes caused by human activity (climate change)
Sustainability
New pests and pathogens
What affects the rate of decay?
Temperature - warmer temp speeds it up
Water content - faster in moist environments
Oxygen availability - faster when there’s plenty of oxygen
What food preservation methods reduce the rate of decay?
Storing food in the fridge/freeze lowers the temperature.
Storing food in airtight cans stops microorganisms getting in.
Drying foods removes the water that microorganisms need to survive and reproduce.
