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A-level biology > 4.2.1 - biodiversity > Flashcards

4.2.1 - biodiversity Flashcards

(48 cards)

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1
Q

what is biodiversity

A

a measure of the variation found in the living world

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2
Q

what is a habitat

A

a place where species live

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3
Q

what is habitat diversity

A

habitats can range in size and structure and each habitat is occupied by a range of organisms

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4
Q

what is a species

A

a group of organisms similar in appearance and can breed to produce fertile offspring

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5
Q

what is species richness

A

a measure of how many different species are present

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6
Q

what is species evenness

A

a measure of how evenly represented a species are

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7
Q

what is genetic biodiversity

A

variation between individuals of the same species which can create breeds between species

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8
Q

how do you do random sampling

A

sample coordinates are selected using a random number generator and this is done before arriving on the site to reduce bias

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9
Q

positives of random sampling

A

data not biased

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10
Q

negatives of random sampling

A

may not cover all areas equally and species with lower presence may be missed

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11
Q

ways that you can trap invertebrates

A

sweep nets, pitfall trap, Tullgren funnel, pooter

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12
Q

how do you use a sweep net

A

walk through a habitat with a sweep net and sweep the net through vegetation in wide arcs

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13
Q

what is a pitfall trap

A

a trap set in the soil to catch animals

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14
Q

how does a pitfall trap work

A
  • a small container is buried in the soil so the rim is just below the surface and any animals moving through will fall into the trap
  • trap should contain some water or scrunched up paper so the animals don’t crawl out again
  • in rainy weather, the trap should be sheltered from the rain so it doesn’t fill up
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15
Q

what is a Tullgren funnel

A

A device for collecting small animals from leaf litter

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16
Q

how does a Tullgren funnel work

A
  • place the leaf litter in a funnel and the light above the litter drives the animals down as the litter dries out and warms up.
  • they fall through the mesh screen and are collected in a jar under the funnel
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17
Q

How does a light trap work

A
  • consists of a UV light attracting the insects.
  • Under the light is a collecting vessel containing alcohol. Moths and other insects attracted to the light eventually fall into the alcohol
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18
Q

what is systematic sampling

A

transect is used when the environment changes from 1 place to another. Samples are taken at fixed intervals along a line laid out across a habitat

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19
Q

positives of systematic sampling

A

useful when habitat shows a clear gradient in environmental factors - ie grassland to woodland

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20
Q

negatives of systematic sampling

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A

only species on the line/belt are measured leading to an underestimate

21
Q

what is stratified sampling

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A

divide habitat into areas which appear to be different and sample each section separately

22
Q

positives of stratified sampling

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A

ensures all areas of the habitat are samples and species are not under represented

23
Q

negatives of stratified sampling

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A

may lead to overrepresentation or there could be a disproportionate number of samples taken

24
Q

what is opportunistic sampling

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A
  • researcher takes samples based on prior knowledge or during the process of collecting data
    • they may sample an area they know contains a particular species
25
positives of opportunistic sampling
easier and faster than random sampling
26
negatives of opportunistic sampling
data may be biased or there may be an overestimation
27
how is species richness measured
taking random samples and counting the species present A higher species richness indicates a greater diversity
28
how is species evenness measured
taking samples and counting individuals of each species more evenness indicates diversity
29
what does simpsons index of diversity measure
the diversity of a habitat
30
what does n stand for in simspons index of diversity
total number of organisms in 1 species
31
what does N stand for in simpsons index of diversity
total number of all organisms
32
what does a higher value of simpsons index of diversity mean
- it is more diverse - the habitat provides a place for many different species and organisms to live - each species only represents a relatively small proportion of the habitat - any change affecting 1 species tends to have a small effect on the whole habitat - it is more likely to withstand change
33
what is polymorphsim
when a gene has more than 1 allele
34
example of a gene with polymorphism
hair/eye colour
35
what is monomorphism
when a gene only has 1 allele
36
what do monomorphic genes ensure
ensures that the basic structure of the species is similar
37
proportion of polymorphic gene loci
= number of polymorphic gene loci/total number of loci
38
why should biodiversity be maintained
- to maintain interdependence - we can source medicine - mangroves and coral reefs protect from extreme weather such as storm surges - to maintain aesthetics - economic reasons - ecological reasons
39
human activities that reduce biodiversity
- cutting down trees - pollution - water pollution (affects species drinking from it/living in it) - burning coal (releases greenhouse gases and causes global warming) - hunting animals - overfishing
40
ways we can maintain biodiversity
- afforestation (replanting trees) - cutting carbon emissions - use renewable energy - consume less and responsibly - eat meat and dairy responsibly - reduce food waste - educate people - introducing laws and policies
41
ecological reasons for maintaining biodiversity
- protecting keystone species - a species that has a disproportionate effect in its habitat - ex - wolves in Yellowstone National Park - maintain interdependence of organisms
42
economic reasons to maintain biodiversity
- there are resources such as food - nature does a lot of processes on its own such as pollination which would be expensive and time consuming for humans to do - avoid monoculture - habitat with only one species - if a new disease kills 1, all will be killed - reduced biodiversity
43
aesthetic reasons to maintain biodiversity
ecotourism can be done
44
what are the main conservation agreements to protect species and habitats
- Convention on International trade in endangered species (CITIES) - The Rio convention of biological diversity (CBD) 1992 - Countryside stewardship scheme (CSS) 1991 (CSS was replaces by the environmental stewardship scheme (2005))
45
what are the aims of the CITIES agreement
- regulate and monitor international trade in selected species of plants and animals - ensure that international trade does not endanger the survival of populations in the wild - ensure that trade in wild plants for commercial purposes is prohibited - ensure that trade is artificially propagated plants is allowed, subject to permit - ensure that some slightly less endangered wild species may be traded subject to permit, as agreed between the exporting and importing countries
46
what are the aims of the CBD agreement
- develop international strategies on the conservation of biodiversity - using plant and animal products in a sustainable way - appropriate shared access to genetic resources - appropriate sharing and transfer of scientific knowledge and technologies - fair and equitable sharing of the benefits arising out of the use of genetic resources
47
what are the aims of the CSS scheme
- improve the natural beauty and diversity of the countryside - enhance, restore and re-create targeted landscapes, their wildlife habitats and historical features - improve opportunities for public access
48

A-level biology (25 decks)

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