Biodiversity -Spec

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  • Created by: rachel
  • Created on: 22-03-13 20:43
Define the term species.
A group of individual organisms which are very similar in appearance, anatomy, physiology, biochemistry & genetics, whose members are able to interbreed freely to produce fertile offspring.
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Define the term habitat.
The place where an organisms lives.
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Define the term biodiversity.
The
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Explain how biodiversity may be considered in terms of habitats.
The range of habitats in which different species live.
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Explain how biodiversity may be considered in terms of species.
The number of different species.
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Explain how biodiversity may be considered in terms of genetics.
Genetic variation between individuals within a species.
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Explain the importance of sampling in measuring the biodiversity of a habitat.
Human activities affect environment in variety of ways. Unless we study effects, cannot access impact we have. Env impact assessments are v. important parts of planning process & used to estimate the aspects of planned development on environment.
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Describe how random samples can be takes when measuring biodiversity.
Biodiversity:All individuals of all species are counted -> Impractical (1000's of single-celled organisms per square m of soil). So, habitat is randomly sampled - random portions of habitat selected & studied in detail. Results multiplied as estimate
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When sampling plants, what are the three ways of randomly selecting areas?
1) Taking samples at regular distances across habitat. 2) Using random numbers to plot coordinates within habitat. 3)Selecting coordinates from a map & then using a GPS to find position inside habitat.
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What are the two main ways to measure the biodiversity of plants.
Random Quadrats & Transects.
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Describe measuring biodiversity by using random quadrats.
Quadrat is places at random on habitat & plants within it are identified. Their abundance is then measured in one of 3 ways: An abundance scale, Percentage cover, Point frame.
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How would you go about measuring the abundance of plants through an abundance scale?
Each species in the quadrat has an abundance score applied to it.
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How would you go about measuring the abundance of plants through percentage cover?
The percentage cover of each plant in the quadrate is estimated. Sometimes the quadrat is divided into 100 squares to make this easier.
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How would you go about measuring the abundance of plants through a point frame?
A frame holding a number of long needles, usually 10, are used to measure % cover. Each plant touching the needle is recorded. If the frame is used 10 times, each plant recorded will have a 1% cover.
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Describe how you would measure the biodiversity of plants through Transects.
A long rope of tape measure is stretched across the habitat & samples are taken along the line.
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Describe how you would measure the biodiversity of plants through a line transect.
Record the plants touching the line at set intervals.
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Describe how you would measure the biodiversity of plants through an interrupted belt transect.
A quadrat is used at set intervals along the line.
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Describe how you would measure the biodiversity of plants through a continuous belt transect.
A quadrat is used continuously along the transect.
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What is animal sampling?
Where smaller animals can be trapped, their numbers observed, the total population estimated. Larger animals cannot be trapped. They must be carefully observed & their numbers estimated.
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Describe how you can sample animals through sweep netting.
Sweeping a net through vegetation. Sweep for a set period of time in a number of random areas. Produce a mean of the number of organisms caught. Any organisms that are caught are released.
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Describe how you can sample animals through collecting from trees.
A white sheet is held under a branch & the branch is knocked, so any small animals drop into the sheet.
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Describe how you can sample animals through a pitfall trap.
A container buried in the soil so that it is just below the surface. Any animals moving through the plants or leaf litter will fall into the container.
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Describe how you can sample animals through a tullgren funnel
Leaf litter is placed in a funnel. A light above the leaves drives the animals downwards as the leaf litter dries out & warms up. They fall through the mesh screen into the jar below.
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Describe how you can sample animals through a light trap.
An UV light attracts the insects, which eventually fall into the vessel of alcohol below.
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Describe how to measure species richness in a habitat.
Its the number os species in a habitat. The more species present, the richer the habitat. This can be measured by the methods of animal sampling.
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Describe how to measure species evenness in a habitat.
Its the relative abundance of individuals in each species. This is measured in plants by estimating % cover. Larger animals are observed & counted. Smaller animals are calculated using mark & recapture technique.
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What does the n & N stand for in the equation: D=1-(∑(n/N)2)?
n = no. of individuals of particular species. N = total number of individuals for all species.
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Outline the significance of both high & low values of the Simpson's index of Diversity (D).
High value: diverse habitat that tends to be stable & able to with-stand change. Low value: Habitat dominated by few species & a small change could damage/destroy whole habitat.
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What are the current estimates of global biodiversity.
1,730,000 species in the world & 89,000 in the UK. This isn't a measure of biodiversity because they don't take into account the number of individuals in each species, or give any indication of the variation between or within different species.
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Why can't we be sure about how accurate estimates are of global biodiversity?
Because they don't include any marine species. We cannot be sure that we have found all of the species on earth. Evolution & speciation are continuing. Many species are endangered & some are becoming extinct.
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Other cards in this set

Card 2

Front

Define the term habitat.

Back

The place where an organisms lives.

Card 3

Front

Define the term biodiversity.

Back

Preview of the front of card 3

Card 4

Front

Explain how biodiversity may be considered in terms of habitats.

Back

Preview of the front of card 4

Card 5

Front

Explain how biodiversity may be considered in terms of species.

Back

Preview of the front of card 5
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