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A Level Biology > 4.2.1 Biodiversity > Flashcards

4.2.1 Biodiversity Flashcards

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1
Q

What is the same point that alleles of the same gene are found on the chromosome called?

A
  • a locus
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2
Q

Describe some methods of in situ conservation

A

Establishing protected areas such as national parks and wildlife reserves:

  • habitats and species are protected in these areas by restricting urban development, industrial development and farming
  • similar idea has been introduced to sea ecosystems and Marine Conservation Zones where human activities are controlled

Controlling or preventing the introduction of species that threaten local biodiversity

  • e.g. grey squirrels are not native to Britain and they compete with native red squirrels and have caused a population decline
  • therefore, they are controlled in some areas

Protecting habitats:

  • e.g. controlling water levels to conserve wetlands ad coppicing to conserve woodlands
  • this allows organisms to continue living in their natural habitat

Promoting particular species:
- this could be by protecting food sources or nesting sites

Giving legal protection to endangered species:
- making it illegal to kill them

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3
Q

Why is conservation important?

A
  • it is important to ensure the survival of endangered species
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4
Q

Describe how climate change affects global biodiversity

A
  • climate change is the variation in the Earth’s climate
  • occurs naturally, but ATM caused by humans increasing emissions of greenhouse gases
  • these gases cause global warming and climate change
  • climate change will affect different areas differently which affects global diversity
  • most species need a particular climate to survive
  • a change in climate may mean that an area that was previously inhabitable becomes uninhabitable
  • this may cause an increase or decrease in the range of some species, which may increase or decrease biodiversity
  • some species may be forced to migrate to a more suitable area, causing a change in species distribution
  • migrations usually decrease biodiversity in the areas the species migrate from and increase where they migrate to
  • if they cannot find a suitable habitat to migrate, or that it is a plant, or the change is too past, the species may become extinct
  • which decreases biodiversity
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5
Q

Why should the sample be random?

A
  • to avoid bias
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6
Q

Why is international cooperation important in species conservation?

A
  • information about threats to biodiversity needs to be shared and countries need to decide on conservation methods and implement them together
  • it’ll be pointless if one country something is legal and the other is not
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7
Q

Describe two examples of successful international cooperation in species conservation

A

Rio Convention on Biological Diversity (CBD):

  • aims to develop international strategies on the conservation of biodiversity and how to use animal and plant resources in a sustainable way
  • convention made it part of international law that conserving biodiversity is everyone’s responsibility
  • provides guidance to governments on how to conserve biodiversity

CITES Agreement:

  • CITES (Convention of International Trade in Endangered Species) is an agreement designed to increase international cooperation in regulating trade in wild animals and plant specimens
  • member countries all agreed to make it illegal to kill endangered species
  • the agreement helps to conserve species by limiting trade through licensing and by making it illegal to trade in products made from endangered animals
  • also designed to raise awareness of threat to biodiversity through education
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8
Q

Why is maintaining biodiversity important for ecological reasons?

A
  • to protect species, including keystone species:
  • organisms in an ecosystem are interdependent
  • the lost of just one species can have drastic effects on an ecosystem e.g.
    • disruption of food chains
    • disruption of nutrient cycles
  • keystone species are often predators but can also be modifiers (maintaining the environment needed for the ecosystem) or hosts (plants provide habitat)
  • to maintain genetic resources:
  • this is any material from plant, animals or microorganisms containing genes that we find valuable
    1. we need to maintain them because
  • provide everyday products:
      • food and drink
      • clothing
      • drugs
      • fuels
      • industrial materials
  • these are important to the global economy
    2. genetic resources allow us to adapt to changes in the environment
  • climate change may mean some crops won’t grow in the same areas as they do now because e.g. droughts, but we may be able to use the genes to genetically engineer a drought-resistant crop
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9
Q

What is the formula for Simpson’s Index of Diversity?

A

D = 1 - (Σ(n/N)^2)

n = Total number of individuals of one species 
N= total number of organisms of all species
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10
Q

What is the formula for proportion of polymorphic gene loci?

A

proportion of polymorphic gene loci = (number of polymorphic gene loci) / (total number of loci)

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11
Q

What type of population may have low genetic diversity?

A
  • isolated populations

- populations bred in captivity

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12
Q

What is genetic diversity?

A
  • the variation of alleles within a species (or a population of a species)
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13
Q

What is polymorphism?

A
  • describes a locus that has two or more alleles
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14
Q

Define biodiversity

A
  • the variety of living organisms in an area
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15
Q

What is habitat diversity?

A
  • the number of different habitats in an area

- e.g. an area could contain sand dunes, woodland, meadows, streams

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16
Q

What is ex situ conservation?

A
  • off site conservation
  • involves protecting a species by removing part of the population from a threatened habitat and placing it in a new location
  • ex situ conservation is often a last resort
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17
Q

What is species diversity?

A
  • the number of different species (species richness) and the abundance of each species (species evenness) in an area
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18
Q

How could you take a random sample?

A
  • you could pick random sample sites by dividing the field into a grid using measuring tapes
  • use a random number generator to select coordinates
19
Q

What are the advantages and disadvantages to ex situ conservation?

A

Advantages:

  • it can be used to protect individual animals in a controlled environment; e.g. predation and hunting can be managed more easily
  • it can also be used to reintroduce species that have left an area

Disadvantages:

  • usually only a small number of individuals can be cared for
  • can be difficult and expensive to create and sustain the right environment
  • animals that are habituated may be less likely to exhibit natural behaviour and also more likely to catch a disease from humans
  • ex situ methods usually less successful than in situ methods: many species can’t breed successfully in captivity or don’t adapt to their new environment when moved to a new location
20
Q

Describe a local conservation scheme that aims to protect special areas in the UK

A

The Countryside Stewardship Scheme (CSS):

  • CSS was introduced in 1991. aimed to conserve wildlife and biodiversity and improve and extended wildlife habitats by promoting specific management techniques to landowners
  • Government offered a 10 year agreement to pay landowners who followed the management techniques suggested. e.g. regenerate hedgerows, to leave grassy margins around edges of fields where wildflowers could grow, and to graze upland areas to keep down bracken
  • in 2000, there were 10000 agreements in England. since then various species have begun to rebuild in numbers, including birds such as stone curlew, black grouse and bittern
21
Q

What is species evenness?

A
  • a measure of the relative abundance of each species in an area
  • the more similar the population size of each species, the greater the species evenness
  • measured by taking random samples of habitats and counting the number of individuals of each different species
22
Q

Why is maintaining biodiversity important for aesthetic reasons?

A
  • areas rich in biodiversity provide pleasant, attractive landscapes that people can enjoy
  • maintaining biodiversity means protecting beautiful landscapes
  • the more biodiversity in an area the more visitors the area is likely to attract which brings economic advantages
23
Q

How do you carry out sampling?

A
  • choose an area to sample: a small area within the habitat being studied
  • count the number of individuals of each species: quadrat for plants, sweep net for flying insects, pitfall trap for ground insects, net for aquatic animals
  • repeat the process: take as many samples as possible to give a better indication of the whole habitat
  • use the results to estimate the total number of individuals or different species in the habitat being studied
  • always use the same sampling technique when sampling different habitats and comparing them
24
Q

What are the three factors that affect global biodiversity?

A
  • human population growth
  • increased use of monoculture in agriculture
  • climate change
25
Q

Define habitat

A
  • the area inhabited by a species
  • includes the physical (abiotic) factors, like the soil and temperature range and the living (biotic) factors, like availability of food or presence of predators
26
Q

How do you interpret Simpson’s Index of Diversity?

A
  • always a value between 0 and 1

- the closer to 1 the index, the more diverse the habitat

27
Q

Describe some methods of ex situ conservation

A
  • Relocating an organism to a safer area: e.g. 5 white rhinos were relocated from Congo to Kenya because of the danger from poachers
  • Breeding organisms in captivity then reintroducing them to the wild when they are strong enough:
  • e.g. sea eagles have been reintroduced in Britain through a captive breeding programme
  • breeding is carried out in animal sanctuaries and zoos
  • Botanic gardens are controlled environments to grow a variety of rare plants
  • this can be for conservation, research, display and education
  • endangered plant species or species that are extinct in the wild can be grown and reintroduced into suitable habitats
  • seed banks: seeds can be frozen and stored in seed banks for over a century without losing their fertility
  • they provide a useful source of seeds if natural reserves are destroyed e.g. by disease or natural disasters
28
Q

Describe how increased use of monoculture in agriculture affects global biodiversity

A
  • in order to feed an ever growing number of people, larger areas of land are devoted to monoculture, the growing of a single variety of a single crop
  • leads to a decline in global biodiversity because:
    • habits are lost as land is cleared to make way for the large fields, reducing habitat diversity
    • local and naturally occurring plants and animals are seen as weeds and pests, so are destroyed with pesticides and herbicides, reducing species diversity
    • heritage varieties of crops are lost because they don’t make enough money and so are not planted any more, which reduces species diversity
29
Q

Define species

A
  • a group of similar organism able to reproduce to give fertile offspring
30
Q

What does working out the proportion of a polymorphic gene loci in an orgamism do?

A
  • gives you a measure of genetic diversity
31
Q

Describe how human population growth affects global biodiversity

A
  • human population has grown hugely in the last few centuries and is continuing to rise. this decreases global biodiversity because
  • habitat loss: human development is destroying habitats e.g. deforestation in the amazon to make way for grazing and agriculture. this decreases habitat diversity
  • over-exploitation: a greater demand for resources means a lot of resources are being used faster than they can be replenished. e.g. industrial fishing. this decreases genetic diversity within populations, as ell as decreasing species diversity
  • urbanisation: sprawling cities and major road developments can isolate species, meaning population are unable to interbreed and genetic diversity is decreased
  • pollution: high amounts of pollutants can kill species or destroy habitats. e.g. fertiliser killing fish. this decreases biodiversity
32
Q

Why is genetic diversity important?

A
  • if a population has low genetic diversity, they might not be able to adapt to a change in the environment and the whole population could be wiped out by a single event
33
Q

What does in situ conservation mean?

A
  • on site conservation

- involves protecting species in their natural habitat

34
Q

What is species richness?

A
  • the number of different species in an area
  • the higher the number of species, the greater the species richness
  • measured by taking random samples of a habitat an counting the number of different species
35
Q

What are endangered species?

A
  • species which are at risk of extinction because of a low population, or a threatened habitat
36
Q

What are the three types of non-random sampling?

A
  • systematic
  • opportunistic
  • stratified
37
Q

Describe systematic sampling

A
  • when samples are taken at fixed intervals, often along a line
  • e.g. quadrats could be placed along a transect
38
Q

What are the three reasons that maintaining biodiversity is important?

A
  • ecological reasons
  • economic reasons
  • aesthetic reasons
39
Q

Why is maintaining biodiversity important for economic reasons?

A

To reduce soil depletion:

  • monoculture is growing a single variety of a single crop
  • continuous monoculture involves planting the same crop in the same field without interruption
  • this causes soil depletion because the nutrients required are gradually used up
  • the economic costs of soil depletion include increased spending on fertilisers and decreased yields
40
Q

Describe stratified sampling

A
  • this is when different areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole
41
Q

Describe opportunistic sampling

A
  • when samples are chosen by the investigator
  • used because it is simple to carry out
  • but data will be biased
42
Q

What are the advantages and disadvantage of in situ conservation?

A

Advantages:

  • often both the species and their habitat are conserved
  • larger populations can be protected and its less disruptive than removing organic from their habitats
  • chances of the population recovering are greater than with ex situ methods

Disadvantages:

  • it can be difficult to control some factors that are threatening a species
  • e.g. poaching, predators, disease, climate change
43
Q

What does Simpson’s Index of Diversity take into account?

A
  • both species richness and species evens
44
Q

Why is it sometimes necessary to take a non-random sample?

A
  • when there’s a lot of variety in the distribution of species and you want to make sure all the different areas are sampled

A Level Biology (25 decks)

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