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Population Characteristics
Population density – the number of organisms per unit area
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Population Characteristics
Spatial distribution – is the pattern of spacing of a population within an area
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Spatial Distribution Uniform Clumped Random
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Population Ranges No population, not even the human population, occupies all habitats in the biosphere Abiotic factors – temperature, humidity, rainfall or sunlight Biotic factors – predators competitors, parasites
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Population-Limiting Factors
Density-independent factors – any factor in the environment that does not depend on the number of members in a population per unit area Drought or flooding, extreme heat or cold, tornadoes and hurricanes.
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Density-dependent Factor
Any factor in the environment that depends on the number of members in a population per unit area. Predation, disease, parasites, competition.
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Population Growth Rate
How fast a given population grows. Terms Natality – birthrate, the number of individuals born in a given time period Emigration – number of individuals moving away from a population Immigration – number of individuals moving into a population
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Exponential Growth Model
Carrying capacity S-curve Lag phase
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Carrying capacity The maximum number of individuals in a species that an environment can support for the long-term Limited by energy, water, oxygen, nutrients Use this term to describe when a population is stable
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R-strategists Small organisms – fruit fly, mouse, locust
Short life span Produce many Little or no energy to rear young
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K-strategists Large organisms – elephants Long life span Produce few
Time invested in care for the young
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Human Population Human population growth changes over time
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Terms Demography – the study of human population size, density, distribution, movement, and birth and death rates
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Human Population on Earth
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Trends in Human Population Growth
Demographic transition – a change in a population from high birth and death rates to low birth and death rates Zero population growth – when the birth rate equals the death rate Age structure – the number of males and females in each of three age groups of a population, pre- reproductive, reproductive and post-reproductive
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Orca
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I Purpose: What is the difference between a food chain and a food web?
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II Materials: paper, pen
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III Procedures/IV Data & Observations
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III Procedures/IV Data & Observations
List Producers and Consumers Identify with H = herbivore, C = carnivore, O = omnivore, S = scavenger Create a trophic level pyramid
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Trophic Level Pyramid
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Create three food chains
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Create three food chains
phytoplankton krill orca
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Create a Food Web Create on your own!
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V Calculations and Results
Draw a graph 22 boxes across X 20 boxes up
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VI Questions Answer questions 1 – 8 Answer thoughtfully! Homeostasis
|ˌhōmēəˈstāsis|noun ( pl. -ses |-sēz|) the tendency toward a relatively stable equilibrium between interdependent elements, esp. as maintained by physiological processes
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VII Discussion Briefly discuss how this could affect 2 other organisms
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Conclusion Answer your purpose
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Conclusion Answer your purpose
Go back to the first question and answer
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Animal Rights Hearing Next week’s Lab
Need to look up your group’s point of view! Find and bring in an article on your group
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