B2- Understanding Our Environment
- Created by: KatieJ
- Created on: 05-03-14 16:05
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- B2- Understanding Our Environment
- Classification and Living Together
- Organisms are classified into discrete groups
- This causes some problems with: intermediate organisms, hybrids and asexual organisms.
- Organisms can: eat each other (predators), gain from each other (mutualism) or feed off each other (parasites).
- Organisms are classified using natural systems.
- This gives information about evolutionary relationships.
- Similar organisms will compete with each other for food.
- Organisms that share the same niche or are in the same species will compete more.
- Organisms are classified into discrete groups
- Adaption and Natural Selection
- Heat loss from organisms depends on their surface area to volume ratio.
- Organisms in hot, dry areas have adaptions to: increase heat loss, move on sand and cope with a lack of water.
- Organisms in cold conditions are adapted to: keep warm and move on the snow.
- Darwin's theory of natural selection involves variation, competition, survival of the fittest and selective reproduction.
- Darwin's theory was widely criticised at first but is now widely accepted.
- Examples of natural selection occurring today are: warfarin resistance in rats, antibiotic resistance in bacteria and frequency of colour in peppered moths.
- Heat loss from organisms depends on their surface area to volume ratio.
- Population, Pollution and Sustainability
- Pollution can be measured using direct methods or indicator species.
- Human population has been increasing exponentially.
- This has lead to and increase in pollutants, such as: carbon dioxide causing global warming, sulphur dioxide causing acid rain and CFCs breaking down the ozone layer.
- Removing waste, producing food and supplying energy in a sustainable way will help conserve habitats and organisms.
- Conservation is important to:
- Protect our food supply.
- Prevent damage to food chains.
- Protect organisms for medical uses.
- Protect habitats for people to visit.
- Energy Flow and Recycling
- Pyramids of biomass and numbers can show feeding relationships.
- Energy is lost from each stage of a food chain.
- Pyramids of biomass are harder to construct but always form pyramids.
- Food chains are limited to a small number of trophic levels.
- The recycling of nitrogen involves the action of four types of bacteria.
- The recycling of carbon involves: photosynthesis, feeding, respiration and decomposition.
- Classification and Living Together
- Energy Flow and Recycling
- Pyramids of biomass and numbers can show feeding relationships.
- Energy is lost from each stage of a food chain.
- Pyramids of biomass are harder to construct but always form pyramids.
- Food chains are limited to a small number of trophic levels.
- The recycling of nitrogen involves the action of four types of bacteria.
- The recycling of carbon involves: photosynthesis, feeding, respiration and decomposition.
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