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Key Benchmark SC.912.L.17.5 Analyze how population size is determined by: Birth Death Immigration Emigration Limiting Factors ( Biotic and Abiotic)
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Students will Use Data and information about Population dynamics Students will Use graphs and charts to analyze Population change Students need to Explain a change in Carrying Capacity Students must Identify positive/ negative consequences from a reduction in biodiversity Students should determine effects of Limiting Factors
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Questions may include catastrophic events, but the student’s only concern is with the consequence of the event, but not the catastrophe itself. Example: If a flood washes away valuable topsoil and destroys large tracts of land, which graph shows the effect on the native grass population. Students should be able to choose a graph with a down sloping line to indicate a population reduction. *If a trophic level is altered, what is the direct effect on trophic levels above and below?
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Students often think that a catastrophic event or even a change often leads to extinction, when they really need to think in terms of POPULATION REDUCTION It is imperative to have students resist going to the extreme as this will enhance their ability to analyze changes in a more realistic manner.
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Type One: low infant mortality and many survive to old age Type Two: Chance of survival is equal at all ages Type Three: high birth rate and high infant mortality
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See graph on page 439 in Textbook Type One curve is shaped like the top of a football. Most individuals live to maturity and death is usually at older ages. Type one is indicative of large mammals Type Two shows a down sloping diagonal which indicates an equal chance of dying regardless of age. Indicative of many birds. Type Three shows an instant drop indicating high birth rate and high infant mortality. Indicative of fish and insects
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4 Factors Effecting Population Size Birth Death Immigration Emigration Students must be able to analyze a population growth graph and determine which of the 4 factors explains the direction of the graph line.
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Gives us information about species interaction 1. Clumped dispersion: facilitates mating and protection 2. Uniform dispersion: indicates intra-species competition and limited resources 3. Random dispersion: Individuals are spread randomly
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Exponential Growth: Characterized by a “J” curve Indicates very few predators. Ample food supplies Logistic Growth : Characterized by a ‘S” curve Indicates limited resources Predators are present Carrying Capacity is reached
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See textbook page 441 J curve of Exponential Growth shows a steep rise in numbers over a short period of time. Indicative of ample resources like food and shelter Indicates few to No predators
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The “S” curve of Logistic Growth is more reflective of most populations in that initially there is a burst in numbers, but as resources are limited and predators are present, the population line goes horizontal indicating carrying capacity has been reached.
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Students need to remember that a Growth Curve or a Growth Pattern is not set in stone Change is DYNAMIC Change is the Norm Nothing is Fixed Variation Occurs Cause and Effect are your primary focus
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Primary succession establishment of an ecosystem from bare rock First organisms in are pioneer species. Secondary succession Reestablishment of a damaged ecosystem Plants and organisms that remain start the process Reestablishment begins with previous inhabitants *** see questions 7, 14, 21, 23,
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Benchmark Focus: Know seasonal variations Climate zones and Seasonal changes Succession Content Limitations No need to know characteristics of individual biomes Only understand consequence of change in climate or changes due to a catastrophic event.******
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I want my students to know biomes based on “ EST “ Wettest Hottest Driest Newest Largest Most Diverse (est) keep the theme going
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Greatest Diversity Highest Rainfall amount (wettest) Highest Avg. Temp Highest Density of living things
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Largest Land Biome 4 Season Climate with a Severe Winter Dominant Plant: Conifer Trees
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Newest/ Youngest Biome Created by retreating glaciers from Ice Age Coldest Biome Second driest Treeless Only Biome with Permafrost
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Driest Biome/ Least amount of Rainfall Largest Daily Temperature shift between Night and Day Most sparsely populated
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Temperate tells you it has a 4 season Climate Deciduous Trees indicate a true winter Noted for multiple Strata: some say 3: Trees, Shrubs, Ground cover some say 5: Trees, Sapling, Shrub, Herb, Ground cover
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Focus should be on life in the aquatic systems as a function of: Chemistry - oxygen levels-nutrient cycling and seasonal variation Oxygen levels due to water temperature “Turn over” as a result of density differences Light – sunlight is the major abiotic factor Salinity Temperature Depth
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Oxygen levels fluctuate with Temperature Colder water has higher levels of oxygen. Salt water is more DENSE than fresh water Cold water is more DENSE than warmer water Nutrient Turnover is often the result of temperature and density differences occurring as a result of Seasonal Change
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Students do not need to have particular knowledge of individual marine zones See Ecology Population3 questions 8, 9,25 and 30
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