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Define The following Levels:
Biosphere
Biome
Ecosystem
Community
Population
Species
Biosphere- Combined portion of the planet in which all of life exists includig land, water, and air
Biome- group of ecosystems that have the same climate and similar dominant communities
Ecosystem- a collection of all the organisms that live in a particular place combined with there physical environment
Community- an assemlafe of different populations that live together in a defined area
Population- a froup of individuals that belong to the same species and live in the same area
Species- a group of organisms so similar to one another that they can breed and prduce fertile offspring
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Describe the basic approches to ecological research
- Observing- simple or complex
- Experimenting- set up arteficial environments in a lab to test hypotheses
- Model building- a way to study/interpret/explain very complex phenomena and are tested with real life data.
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what percent of all the sun's energy is actually used by plants?
0.1%
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Of the energy that a plant gets, how much is stored in the plant?
50%
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Describe the different levels of consumers
- Primary consumers- eat plants
- Secondary- feed on primary
- Tertiary - feed on secondary
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What is biomass?
The total mass of all organisms in a trophic level
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Describe the three Ecological pyramids
Energy Pyramid- Shows the relative amount of energy available at each trophic level. At each new level there is 10% of the energy of the last level
Biomass Pyramid- Represents the amount of loving organic matter at each trophic level
Pyramid of numbers- Shows the relative number of individual organisms at each trophic level.
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Why do all organisms require nitrogen?
- to build protiens and genetic material.
- free nitrogen makes up 78% of our air!
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Define Nitrogen fixation
Bacteria that live on the roots of some plants capture nitrogen gas and fix (glue) the nitrogen into chemical compounds
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plant and animal remains and other dead matter are collectively called______
detritus
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what does a food web link together?
all the food chains in an ecosystem
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Why is carbon especially important to living systems?
It's the key ingredient in all living organisms
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what is dentrification
other soil bacteria convert nitrates into nitrogen gas.
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what is the main resevoir of nitrogen in the biosphere?
the atmosphere
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when is a substance called a limiting nutrient?
when it is scarce or cycles very slowly
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what is symbiosis?
any relation in which 2 species live closely together
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describe the following relationships:
Murualism
Commensalism
Parasitism
- Mutualism- both species benefit
- commensalism- one benefits, the other is not harmed
- Parasitism- one lives on the other and harms it
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what is ecological succession?
series of predictable changes that occurs in a community over time
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what is primary succession?
succession that occurs on surfaces where no soil exists(volcanic islands)
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The mechanism of population control in which a population is regulated by predation is called a ____
Predator-prey relationship......=GOOD!
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Give exaples of desity-independent limiting factors.
weather, natural disaster, seasonal cycles, certain human activities
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what is biodiversity?
the sum total of the genetically based variety of all organisms in the biosphere (variety)
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Define Ecosystem diversity
the variety of habitats, communities, and ecological prcesses in the living world
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define species diversity
the number of different species in the biosphere
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define genetic diversity
total of all the different forms of genetic ingormation carried by all organisms living on Earth today
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Why is biodiversity one of Earth's greatest natural resources?
species of many kinds have provided us with foods, industrial producs, and medicines
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the process of splitting a habitat into small pieces is called ____
habitat fragmentation
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what is biological magnification?
the concentration of a harmful substance increasing in organisms at higher trophic levels in a food chain or web
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why do invasice species roproduce rapidly and increase their populations?
their new habitat lacks parasites and predators that control ther population "back home"
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