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Definition
a group of organisms of the same species that live in a particular area |
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Term
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Definition
= change in number of individuals __________________________________ time period |
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Term
What factors play a role in an area's growth rate? |
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Definition
birth rage, immigration, death rate and emigration |
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Term
What is the difference between immigration and emigration? |
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Definition
immigration - movement of organisms into an area
Emigration - movement of organisms out of an area |
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Term
Explain what the age structure of a population means. |
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Definition
Age structure means the proportion of individuals in a population that are young, old and in between |
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Term
How do scientists use an area's age structure to make predictions about changes in a population? |
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Definition
Determines future needs for communities |
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Term
What is exponential growth? |
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Definition
Occurs when the rate of population in each new generation doubles itself |
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Term
What is the difference between abiotic and biotic resources? |
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Definition
Abiotic - Nonliving part of an environment, such as water, soil, light, temperature and wind
Biotic - living part of an environment, such as a plant, animal or other organisms |
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Term
What is a limiting factor? |
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Definition
Any biotic or abiotic resource in the environment that limits the size of a population
Examle: land, waer, food, sunshine |
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Term
Define: Carrying Capacity |
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Definition
It is the number of individuals in a population that an environment can support over a relatively long period of time |
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Term
What causes populations to increase? |
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Definition
Lots of food, low diseases, lots of water, few predators, good shelter |
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Term
What causes populations to decrease? |
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Definition
Low amount of food, high disease, low water, lots of predators, poor shelter |
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Term
How do limiting factors in the environment keep the population size in check? |
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Definition
Either cause a decrease in the birth rate or an increase in the death rate |
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Term
Define: Density dependent limiting factors |
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Definition
Only become limiting when the population density - the number of organisms per unit of space reaches a certain level |
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Term
What are some density dependent limiting gators? |
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Definition
living space, disease, competition, predation |
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Term
What is density - independent limiting factors? |
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Definition
Factor that affects all populations regardless of their population density |
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Term
What are some density independent limiting factors? |
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Definition
Weather, seasonal cycles, natural disasters |
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Term
What has happened to the Earth's human population over time? |
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Definition
Was slow - now the population doubling time is getting shorter and shorter. Scientists estimate population grows 90 million people every year |
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Term
Why are ecologists concerned about Earth's increasing population? |
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Definition
Huge demand on natural resources, food, space, etc. |
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Term
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Definition
A collection of populations that interact with each other in a given area |
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Term
What are the levels of organization? |
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Definition
organism population community ecosystem |
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Term
What are invasive species? |
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Definition
Nonnative plants and animals (not original to an area) Invasive means.. invader |
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Term
What are some invasive species in Michigan? |
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Definition
Asian carp round goby purple loosestrife feral pigs sea lamprey zebra mussels mute swan |
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Term
Why are invasive species bad for our environment? |
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Definition
* No predators to kill them * pose a threat to our ecosystems * hard to get rid of |
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How do invasive species come to Michigan? |
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Definition
intentionally and accidentally |
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Term
How are invasive species managed? |
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Definition
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What is the main cause for invasive species spreading so quickly? |
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Definition
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Term
How do the different populations interact with each other? |
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Definition
compete for resources - food, water, shelter, etc. Prey on one another |
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Term
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Definition
a particular role that a population plays in its community |
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Term
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Definition
the natural home or environment of an animal, plant or other organism |
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Term
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Definition
An organism that eats other organisms |
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Term
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Definition
An organism eaten by another organism |
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Term
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Definition
When one species lives in close association with another species over a period of time |
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Term
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Definition
2 species interact closely in a way that benefits both species |
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Term
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Definition
Where one species benefits and the other is harmed |
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Term
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Definition
one organism benefits from the relationship and the other organism in NOT helped or harmed |
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Term
Why is genetic diversity within populations important in maintaining ecological balance in a community? |
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Definition
A population with high genetic diversity will survive because their genetic make up makes them more resistant to disease |
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Term
What is ecological succession? |
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Definition
A change in the community resulting in new populations of organisms gradually replacing existing ones |
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Term
What is primary succession? |
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Definition
A process that occurs when a new community arises from a previously lifeless habitat Begins with bare land - NO soil is present |
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Term
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Definition
One of the first plants to get established in a pioneer community They release a weak acid to help break down rock and trees, etc. |
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Term
What is a pioneer community? |
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Definition
The first organisms to occupy an area previously uninhabited by its species |
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Term
What is a climax community? |
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Definition
An established community that encounters little ecological succession * Has reached stability |
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Term
Define - Secondary succession |
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Definition
The development of a new community in a previously occupied habitat * already begins with soil |
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Term
What is aquatic succession? |
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Definition
Water fills in a pond to make it a land ecosystem |
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Term
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Definition
A process of a body of water becoming nutrient rich |
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Term
What are the main sources of eutrophication? |
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Definition
sewage plans, agriculture run off, fertilizers |
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Term
What are the main chemicals that cause eutrophication? |
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Definition
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Term
Secondary succession occurs faster than primary succession - T or F |
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Definition
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