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Varying Populations & Human Populations. By Nick Logan. A load of boring Biology terms you need to know…. Environment – Set of conditions which an organisms exists in – containing abiotic and biotic components Abiotic – Non living factors Biotic – Living factors
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Varying Populations & Human Populations By Nick Logan
A load of boring Biology terms you need to know…. • Environment– Set of conditions which an organisms exists in – containing abiotic and biotic components • Abiotic– Non living factors • Biotic– Living factors • Habitat – The place within the ecosystem that an organism lives in • Ecosystem – Made up of a community of living organisms and biotic factors • Community – is all the populations of different organisms living and interacting in a certain area at a certain time • Niche– Where an organism is found within the habitat AND how that organism fits into its environment. Its role in a habitat
Population – A group of interbreeding organisms belonging to the same species
Varying Populations • Sigmoid Population Curve http://www.youtube.com/watch?v=Vpt34kNFn9k
Population Size • Limiting Factors, such as….? They can be either abiotic or biotic factors • Temp, light, pH, water concentration, humidity • Competition, predation
HUMAN POPULATIONS!!! • Cheeky bit of Attenborough…… http://www.youtube.com/watch?v=LwgO3i_M0tY&feature=related
Factors that Affect Birth Rate • Economic conditions • Cultural & Religious Backgrounds • Social Pressures • Birth Control • Political Factors
Factors that Affect Death Rate • Age profile • Life expectancy at birth (IFM) • Food supply • Availability of safe drinking water • Effective sanitation • Quality of medical care • Natural disasters • Wars
Population Structure • Demographic Transition Model - change in societies from a……
Population Pyramids • Stable Population - birth and death rate are in equilibrium. Therefore no change in population size • Inc. Population - high birth rate = wide base - typical of LEDC’s • Dec. Population - low birth rate = narrow base - lower mortality rate = more old people - occurs in MEDC’s