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Biodiversity Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

What is biodiversity?

A

The variety of living organisms in an area

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2
Q

What is a species?

A

A group of similar organisms that can reproduce to give fertile offspring

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3
Q

What is a habitat?

A

The area where an organism lives

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4
Q

What is habitat biodiversity?

A

The number of different habitats in an area. An area could have many different habitats such as woodland, meadows and streams

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5
Q

What is species biodiversity?

A

The number of different species (species richness) and the abundance of each species (species evenness)

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6
Q

What is genetic biodiversity?

A

The variation of alleles within a species. This creates different breeds of dogs.

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7
Q

The steps of sampling

A
  1. Choose an area to sample
  2. Count the number of each species
  3. Repeat process to get lots of different samples
  4. Use results to estimate the total number of species/individuals in a habitat
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8
Q

How to carry out random sampling

A

Sample sites in habitat are randomly selected, e.g use a random number generator to generate coordinates

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9
Q

What are the advantages of random sampling?

A

Ensures the data is not biased

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10
Q

What are the disadvantages of random sampling?

A

May not cover all areas of the habitat equally. Species with a low presence could be missed. This could lead to an underestimate of biodiversity.

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11
Q

What is opportunistic sampling?

A

A type of non random sampling when samples are chosen by the investigator. The researcher may deliberately sample an area where they know contains a particular species.

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12
Q

What are the advantages of opportunistic sampling?

A

Easier and quicker than random sampling

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13
Q

What are the disadvantages of opportunistic sampling?

A

The data may be biased.
The presence of large or colourful species may entice researcher.
This may lead to overestimate in its importance and an overestimate of biodiversity.

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14
Q

What is stratified sampling?

A

Where different areas of a habitat are identified and sampled separately in proportion to their part of the habitat as a whole.
The habitat is divided into areas that appear different and each area is sampled separately.

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15
Q

What are the advantages of stratified sampling?

A

Ensures all different areas of a habitat are sampled and species are not under-represented due to possibility that random sampling might miss certain areas.

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16
Q

What are the disadvantages of stratified sampling?

A

May lead to over representation of some areas in the sample

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17
Q

What is systematic sampling?

A

When samples are taken at fixed intervals, often along a line. E.g line transects and belt transects

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18
Q

What are the advantages of systematic sampling?

A

Useful when habitat shows a clear gradient in an environmental factor such as getting drier further from a pond.

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19
Q

How to sample plants

A

Use a quadrat

Percentage cover can be measured using a point frame

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20
Q

How to sample animals

A

For flying insects use a sweep net
For ground insects use a pitfall trap
For aquatic animals use a net

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21
Q

What is a tullgren funnel?

A

Used to collect small animals from leaf litter. A light above the litter drives the animals downwards and they fall through mesh to be collected in a jar underneath.
A light trap can be used to trap flying insects at night. The jar contains alcohol, insects are attracted to the light and fall into the alcohol.

22
Q

Capture recapture method

A

capture a sample of animals and mark them C1. Release and leave for a period of time. The number of captured the second time is C2. The number captured the second time that were already marked is C3.

(C1 x C2)/C3

23
Q

What is Simpson’s index of diversity?

A

D = 1 - (sum of(n/N)^2)
It is the measure of diversity in a habitat
It takes into account species evenness and species richness
The value will be between 0 and 1. The closer to 1 the more diverse the habitat. The greater the species evenness and richness.
n is the number of individuals of one species
N is the total number of organisms of all species

24
Q

How to measure genetic diversity

A

Genetic diversity is found where there is more than one allele at a particular locus. This will lead to variations between individuals that can be observed.

25
Q

Where might genetic diversity be low?

A

In isolated populations

zoos

26
Q

Why is genetic diversity important?

A

If genetic diversity is low, they might not be able to change and adapt to the environment so they could be easily wiped out by a single change.

27
Q

What is polymorphism?

A

A locus that has two or more alleles.

28
Q

How to calculate genetic diversity

A

Genetic diversity can be estimated by calculating the number of loci in one individual that are heterozygous.

Proportion of polymorphic gene loci = number of polymorphic gene loci/ total number of loci

29
Q

What factors affect biodiversity?

A

Human population growth
Agriculture
Climate change
Extinction

30
Q

How does human population growth affect biodiversity?

A

Habitat loss - human development is destroying habitats which decreases habitat diversity
Over exploitation - greater demand for resources means they are being used up faster than they can be replenished E.g industrial fishing could cause extinction which decreases genetic diversity and species diversity
Urbanisation - cities and road developments can isolate species so populations are unable to interbreed which decreases the genetic diversity
Pollution - pollutants can kill species and destroy habitats which decreases biodiversity

31
Q

How does agriculture affect biodiversity?

A
  • Habitats are lost as land is cleared for fields which reduces habitat diversity
  • local and naturally occurring plants and animals are seen as weeds and pests so are killed, this reduces species diversity
  • Heritage varieties of crops are lost if they don’t make enough money and are no longer planted. This reduces species diversity.
  • monoculture involves planting crops of just one strain of one species
  • selective breeding also reduces genetic diversity
32
Q

How does climate change affect biodiversity?

A

Most species need a particular climate to survive. Id there is a change in the climate, this may make an area become uninhabitable. Some species may be forced to migrate causing a change in species distribution and decreasing species diversity in the area they migrated from. If they can’t migrate, they may become extinct decreasing the species diversity.
Domesticated plants and animals that have been selectively bred will find it difficult to adapt due to lack of variation.

33
Q

Ecological reasons to maintain biodiversity (Interdependence)

A

Organisms in an ecosystem are interdependent and rely on each other to survive. The loss of keystone species can have drastic effects. This can disrupt food chains and and nutrient cycles. This will affect the growth of plants and amount of food available to animals.

34
Q

What is a keystone species?

A

A species of which many other species depend on. If the keystone species became extinct the ecosystem would change dramatically.
They are often predators as they keep the population of their prey in check. Could also be modifiers which maintain the environment needed for an ecosystem such as beavers building dams. Could be hosts which are plants that provide a particular environment.

35
Q

Reasons to maintain biodiversity (genetic)

A

TO MAINTAIN GENETIC RESOURCES
Genetic resources provide us with everyday products such as food, drinks, clothing, drugs, fuels and other materials.
They allow us to adapt to changes in the environment. We can use genes from a plant that is resistant to drought to genetically engineer a drought resistant crop.

36
Q

Economic reasons to maintain biodiversity

A

Impact of food production. To reduce soil depletion. Soils subjected to monoculture become less fertile because the nutrients get used up so agricultural yields decline.

37
Q

How ecosystems are of value to humans

A
  • Regulation of atmosphere and climate
  • purification and retention of fresh water
  • formation and fertilisation of soil
  • recycling of nutrients
  • detoxification and recycling of wastes
  • crop pollination
  • growth of timber, food and fuel
  • discovery of molecules with potential as medicines
38
Q

Aesthetic reasons to maintain biodiversity

A

Areas rich in biodiversity provide pleasant, attractive landscapes that people can enjoy.
Maintaining biodiversity protects these landscapes.
Also attracts tourism (economic advantages)

39
Q

What is in situ conservation?

A

Involves protecting species in their natural environment. It involves attempting to minimise human impact on the natural environment.

40
Q

Methods of in situ conservation (5)

A
  1. Wildlife reserves - habitats and species are protected by restricting urban development, industrial development and farming.
  2. Controlling or preventing the introduction of species that threaten local biodiversity. E.g grey squirrels controlled to help reds
  3. Protecting habitats - controlling water levels in wetlands and coppicing trees in woodland to allow organisms to continue living in their natural habitat
  4. Promoting particular species - by protecting food sources or nesting sites
  5. Giving legal protection to endangered species
41
Q

Advantages of in situ conservation

A
  • Plants and animals conserved in natural environment so less disruptive
  • permanently protects the biodiversity in the ecosystem
  • allows management of these areas
  • both species and habitat are conserved
  • Larger populations can be protected
  • can be used for outdoor activities and have economic benefits
  • facilitates scientific research
42
Q

Disadvantages of in situ conservation

A
  • can be difficult to control some factors that threaten a species such as poaching, predators, disease or climate change.
  • Endangered habitats may be fragmented
  • Population may have already lost much of its genetic diversity
  • Conditions that caused the habitat or species to become endangered may still be present
43
Q

What is ex situ conservation?

A

Protecting a species by removing part of the population from a threatened habitat and placing it in a new location

44
Q

Methods of ex situ conservation (4)

A
  1. Relocating an organism to a safer area
  2. Breeding organisms in captivity then releasing them back into the wild when they are strong enough again, this is carried out in zoos or animal sanctuaries
  3. Botanic gardens are controlled environments used to grow rare species of plants for conservation, education, research and display. Endangered/extinct plants can be reintroduced into the wild
  4. Seed banks - seeds can be frozen and stored and remain viable for a long time. Provide a useful source of seeds if natural reserves are destroyed.
45
Q

Advantages of ex situ conservation

A
  • protection from predation and poaching
  • health of individuals can be monitored and medical help given when required
  • genetic diversity can be measured and selective breeding can increase genetic diversity
  • IVF can increase reproduction chances
  • Can be bred to increase numbers
46
Q

Disadvantages of ex situ conservation

A
  • usually only a small number of individuals can be cared for
  • likely to have limited genetic diversity
  • living outside natural habitat
  • can be difficult and expensive to sustain the correct environment for survival
  • less likely to behave normally, reproduction could be difficult
  • more likely to catch diseases
  • when released to wild, many will find it difficult to adapt
47
Q

Why is ex situ conservation easier for plants than animals?

A
  • as seeds are produced in large numbers, they an be collected from wild without disturbing ecosystem or the wild population
  • seeds can be stored and germinated in protected environments
  • seeds can be stored in large numbers without occupying a lot of space
  • plants can often breed asexually
48
Q

What is the Rio Convention on Biological Diversity (CBD)?

A

Aims to develop international strategies on the conservation of biodiversity and how to use animal and plant resources in a sustainable way.
Made it part of international law that conserving biodiversity is everyone’s responsibility.
Provides guidance to governments on how to conserve biodiversity.

49
Q

What is the Convention on International Trade in Endangered Species (CITES)?

A

Increase international cooperation in regulating trade of plant and animal specimens.
Member countries make it illegal to kill endangered species.
Limits trade by licencing and making it illegal to trade products from endangered animals.
Raises awareness of threats to biodiversity by education.

50
Q

What is the Countryside Stewardship Scheme (CSS)?

A

Local conservation to protect areas in the UK
Aims to conserve wildlife and biodiversity and to improve and extend wildlife habitats by promoting specific management techniques.
Aims to enhance restore and recreate targeted landscapes, their wildlife habitats and historical features.
Aims to improve opportunities for public access.

Biology (16 decks)

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