Biology > Biodiversity > Flashcards

Biodiversity Flashcards

(57 cards)

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1
Q

Define biodiversity

A
  • The variability within species, between species and between ecosystems
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2
Q

Why is biodiversity important?

A
  • biodiversity is essential in maintaining a balanced ecosystem
  • all species are interconnected (depend on one another), in reduced biod these connections may not be present which harms all species in ecosystem
  • rely on balanced ecosystems to provide us with food, oxygen and materials
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3
Q

What is an EIA and why is it necessary?

A
  • Environmental impact assessment
  • gives information about species present
  • assesses positive and negative effects of a project on the biodiversity of an area
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4
Q

What is habitat biodiversity?

A
  • The range of different ecosystems or habitats within a particular region
  • E.g it is low in the arctic but high in a rainforest
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5
Q

What is species biodiversity?

A
  • the number and variation of species within an area
  • measured using a combination of richness/ evenness
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6
Q

What is genetic biodiversity?

A
  • variation between individuals belonging to the same species
  • this is the variation found within any species that ensures we do not look identical
  • measured by allele frequencies
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7
Q

What is sampling?

A

Sampling means taking measurements of a limited number of individual organisms present in a particular area..

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8
Q

Why do we use sampling?

A
  • Look at the effect of disease
  • indicator of climate change
  • indicator of habitat change
  • can be used to estimate no of organisms in an area without counting them all
  • can be used to measure a particular characteristic
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9
Q

Describe the procedure of random sampling

A
  • Selecting by chance
  • number tables or a computer can be used
  • coordinates could be selected on a map before sampling
  • lay out two tapes at right angles, use random numbers to select x+y coords
  • use quadrat at each set of coords and repeat
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10
Q

Describe the procedure of opportunistic sampling

A
  • researcher makes sampling decisions based on prior knowledge or during sampling
  • researcher may deliberately sample an area that is known to contain a particular species
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11
Q

Describe the procedure of stratified sampling

A
  • Populations divided into strata based on a characteristic
  • a random sample is taken from each strata proportional to its size.
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12
Q

Describe the procedure of systematic sampling (line)

A
  • Line
  • samples taken at fixed intervals across a habitat
  • samples touching the line are counted
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13
Q

Describe the procedure of systematic sampling (belt)

A
  • samples taken at fixed intervals across a habitat
  • provides more information than line as sampling it at intervals between two parallel lines
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14
Q

What is sampling bias?

A
  • Deliberately choosing an area which appeals to the researcher
  • Reduced by using random sampling as the area being sampled will be as a result of chance not choice
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15
Q

What is meant by chance and how does it affect reliability?

A
  • Organisms being sampled are not as a result of human involvement
  • Organisms selected may not be representative, reduced by large sample size
  • the greater the no of individuals studied, the lower the probability that chance will influence the result.
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16
Q

What are three ways we can sample plant species?

A
  1. Using a point quadrat (pins pushed through at set intervals, species touching pins are counted, frame + horizon bar)
  2. Frame quadrats ( square frame divided into equal sized squares)
  3. Transect line
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17
Q

How do we sample invertebrates?

A
  1. Pooters (sucking on a mouthpiece covered with a filter, draws insects up)
  2. Sweep nets for long grass
  3. Pitfall traps (deep enough to fall in and not crawl out, covered with waterproof tarp to stop rainfall, left overnight for nocturnal species)
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18
Q

How do we sample small animals?

A
  1. Longworth trap= tunnel leads to a nest box with food and nesting material, when it enters it trips a lever and closes door, may be marked when it is released as part of mark-release-recapture
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19
Q

Evaluate random sampling

A
  • Unbiased
  • chosen sample might not respresent the population due to random fluctuations
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20
Q

Evaluate systematic sampling.

A
  • does not involve random elements, performed quickly by a machine
  • method could coincide with a pattern
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21
Q

Evaluate opportunity sampling.

A
  • Quick and easy
  • very biased, no attempt to obtain representative sample has been made
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22
Q

Evaluate stratified sampling.

A
  • enables detailed analysis of sub-groups
  • more complex and time consuming
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23
Q

How do we sample using a point quadrat?

Study These Flashcards
A
  • Frame with a horizontal bar
  • At set intervals long pins are pushed through
  • Each species touching are recorded
24
Q

How can we use frame quadrats?

Study These Flashcards
A
  • Square frame divided into a grid of equal sections
  • Species in squares are counted
25
Describe how to use transects.
- Lay out measuring tape across sample area - at regular distances record species that are touching the line
26
What are pooter traps?
- Suck on a mouthpiece - Causes insects to be drawn into a holding chamber - a filter prevents insects from entering mouth
27
What would we use to capture insects in the wild?
- Sweep nets to sweep the long grass
28
What are pitfall traps?
- Allows small crawling invertebrates to be captured - A hole is dug into the ground - Deep enough that they fall in and can't get out - it is covered with waterproof tarp - left overnight to capture nocturnal creatures
29
Describe what a longworth trap is.
- tunnel leads to a nest box which contains food and nesting material - when the animal enters it trips a lever - causes door to close - may be marked when released (recapture)
30
What is species richness?
The number of the different species in a population
31
What is species evenness?
The distribution of species - if they are evenly distributed in an area - if they are unevenly distributed in an area
32
What does simpson's index of diversity tell us?
- The amount of biodiversity there is in a population - 0= no biodiversity - 1= infinite biodiversity
33
Why is it important to protect low biodiversity areas?
- Organisms in a LB area might be highly adapted to the extreme environment of its habitat - these organisms might not survive elsewhere - important to conserve rare species that may be too specialised to survive elsewhere
34
What is a gene?
A section of DNA found on a chromosome which codes for a protein
35
What is an allele?
- A different form of a particular gene
36
What is meant by locus?
- Specific position of the gene on a chromosome
37
Define genetic biodiversity.
Genetic biodiversity is the variation of genes in a population. In humans genetic biodiversity is the reason why we don't all look the same.
38
How might genetic biodiversity occur?
- Sexual reproduction - interbreeding (results in gene flow (idea of passing on genes from one to another)) - allele mutation
39
What is the benefit of having high genetic biodiversity?
- More stable pop - more likely to survive environmental change - better suited due to variation in alleles - some individuals may have advantageous alleles - species less likely to become extinct
40
How is biodiveristy reduced?
Through decreasing the possible numbers of alleles in a population.
41
State the formula to calculate the proportion of polymorphic gene loci.
Proportion of polymorphic gene loci= no. of polymorphic gene loci/ total number of loci
42
Briefly describe how you might carry out random sampling.
1. Mark out a grid on the area you are sampling (e.g field) using two tape measures laid at right angles 2. use random numbers to determine the x coordinate and the y coordinate on your grid 3. take a sample at each coordinate after generating pairs of coordinates 4. can be done via lottery method or computers
43
What are abiotic factors?
The non-living conditions in a habitat. They have a direct effect on the living organisms that reside there
44
Name some advantages of abiotic factors being quickly and accurately measured
- rapid changes can be detected - human eror in taking a reading is reduced - a high degree of precision can be achieved - data can be stored and tracked on a computer
45
Name examples of abiotic factors
1. wind speed 2. light intensity 3. relative humidity 4. pH 5. temperature 6. oxygen content in water
46
Why is it hard to determine animal pop size?
- Animals are constantly moving through a habitat and others may be hidden
47
How do we estimate animal pop sizes?
- capture-mark-release - time is allowed for organisms to redistribute themselves before another sample is collected - the greater no of marked individuals recaptured= smaller the population
48
How is the number of alleles in a population decreased?
- selective breeding - captive breeding programmes - rare breeds - artificial cloning - natural selection (species evolve to contain alleles that code for advantageous chars) - genetic bottlenecks (few individuals in a pop survive and event of change, reducing gene pool) - founder effect (small no of individuals create a new colony, geogrpahically isolated from the OG) - genetic drift
49
Name an example of a human polymorphic gene.
- Blood type - Ia - Ib - Io
50
What is polymorphism?
Where multiple alleles exist for a gene
51
How has deforestation affected biodiversity?
- It directly reduces the number of trees present - If only a specific type is felled the species diversity is reduced - Reduces the number of animal species present in an area as it destroys their habitat - Animals are forced to migrate to other areas to ensure their survival, may result in biodiversity of neighbouring areas increasing
52
How has agriculture affected biodiversity?
- Removal of hedgerows to enable farmers to use large machinery. Also frees up extra land for crop growing - Use of chemicals such as pesticides and herbicides. Reduces species diversity as it destroys the pest species and in effect destroys food source of other organisms - Herbicides used to kill weeds as they compete with other plants for minerals and light. Food source reduction
53
Explain how climate change affects biodiversity.
- Melting of the polar ice caps could lead to the extinction of few plant and animal species living in these regions - Rising sea levels from melting ice caps and thermal expansion could flood low lying land reducing terrestrial habitats - Saltwater would flow further up rivers reducing the habitats of freshwater plants - Higher temperatures and less rainfall causes some species to not survive, leading to drought resistant xerophytes becoming more dominant Insect life cycles and populations will change as they adapt to climate change.
54
How has population growth affected biodiversity?
- Housing and feeding so many people has accelerated the destruction of natural habitats - More food= more killing and harvesting - Need to clear areas of lands to build more homes for the increasing population - May need to source more medicine so plants like willow (aspirin) and periwinkle (cancer, hodgkin’s) are targeted and collected
55
What are some aesthetic reasons for maintaining biodiversity?
- the presence of different plants and animals enriches our lives - the natural world provides inspirations for people such as writers - studies have shown that patients recover more rapidly from stress and injury when they are supported by plants
56
What are some economic reasons for maintaining biodiversity?
- soil erosion= loss of money as cannot grow or harvest -conserve plants and animals that we use to make things - high biodiversity protects against abiotic stress and disease - highly biodiverse areas attract tourism - plant and animal varities cross breeding
57
Name ecological reasons for maintaining biodiversity.
- all organisms are interdependent on others for survival, removal of one may cause the demise of another - keystone species maintain structures of ecological communities
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