Term
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Definition
| The variety of life in an area as represented by the number of different species present |
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Term
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Definition
| hen the last member of a species dies |
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Term
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Definition
| A time on Earth when many species have gone extinct in a short period of time |
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Term
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Definition
| The variety of genes that are present in a population |
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Term
| Why is genetic diversity important? |
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Definition
| The variety in the population ensures that some members of the population will survive if conditions change |
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Term
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Definition
| The number of different species and their relative abundance (how many there are) in a community |
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Term
| How does species diversity change as you travel from the equator north toward the poles? |
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Definition
| Species diversity drops. There are many more species near the equator than at the poles. |
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Term
| Why are there more species at the equator than the poles? |
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Definition
| The equator receives more sunlight and it is warmer; it is more productive so it can support more organisms |
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Term
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Definition
| The variety of ecosystems that are present in the biosphere |
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Term
| What are direct economic values of biodiversity? |
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Definition
| We gain food, clothing, energy, medicine, and shelter |
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Term
| Why should we be concerned about biodiversity and the future |
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Definition
| Biodiversity may provide us the organisms and genes to help us survive under changing conditions as with the emergence of a new disease that could threaten our food supply. There may also be many undiscovered medicines in plants we have yet to study. |
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Term
| What are indirect economic values of biodiversity? |
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Definition
| We gain oxygen from plants, clean drinking water, protection from floods, drought, fertile soils, etc. |
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Term
| What are aesthetic and scientific values of biodiversity? |
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Definition
| We enjoy the recreation and relaxing beauty of nature, and we may make new scientific discoveries in the future. |
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Term
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Definition
| The gradual process of species becoming extinct |
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Term
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Definition
| The excessive use of a species of economic value |
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Term
| Example of overexploitation |
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Definition
| Hunting passenger pigeons to extinction, hunting the American bison to near extinction |
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Term
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Definition
| An organism can be threatened when its habitat is destroyed by human activity or disrupted when one species is a food web is removed, or degraded by pollution |
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Term
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Definition
| When a habitat is broken into smaller pieces of land |
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Term
| How does habitat fragmentation threaten a species? |
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Definition
| It reduces the amount of area for the organism to live in, it makes it more difficult for members of the population to find each other for mating |
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Term
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Definition
| When the area along the edge of a fragmented habitat has different environmental conditions that the interior of the parcel of land |
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Term
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Definition
| When a pollutant in an ecosystem becomes concentrated as it moves up a food chain |
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Term
| Example of biomagnification |
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Definition
| DDT, an insecticide, existed in very low concentrations in pond water but as it moved up the food chain through phytoplankton, zooplankton, small fish, larger fish to birds like eagles, it became concentrated so that the eagles were unable to lay eggs with strong shells - the shells broke - no chicks!! |
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Term
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Definition
| Air pollution leads to the production of precipitation that has an acidic pH, and this changes the ability of lakes to support life |
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Term
| Introduced or invasive species |
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Definition
| Organisms like plants or animals that are moved from their native ecosystem to a new environment |
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Term
| Why are invasive species a problem |
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Definition
| They threaten the survival of native species because they can out-compete them |
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Term
| Why are invasive species able to survive in their new environments? |
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Definition
| Because they lack predators (for plants, herbivores that would eat them)and diseases to keep their numbers in check |
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Term
| How can we help organisms survive in fragmented habitats? |
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Definition
| Provide then with land corridors that connect the smaller parcels of land and allow organisms to travel from one place to another |
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Term
| What is an endangered species? |
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Definition
| A species of organism whose future survival is under threat due to many different factors such as habitat loss, overexploitation and/or disease; it faces extinction |
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