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Biodiversity Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

Define the term “ecosystem”.

A

All interacting living organisms and the non-living (abiotic) conditions in an area.

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2
Q

Define the term “community”.

A

All the populations of living organisms in a particular habitat.

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3
Q

Define the term “habitat”.

A

The area inhabited by a species.

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4
Q

Define the term “population”.

A

A group of organisms of one species that live in the same place at the same time.

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5
Q

Define the term “species”.

A

A group of organisms which have a common ancestor and can interbreed to produce fertile offspring.

It is the smallest and most specific taxonomic group.

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6
Q

Define the term biodiversity.

A

The variety of living organisms present in an area.

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7
Q

Define the term “habitat biodiversity”.

A

The number of different habitats found within an area.

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8
Q

Define the term “species biodiversity”.

A

The number of different species and the abundance of each species in an area.

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9
Q

Define the term “genetic biodiversity”.

A

The variation of alleles within a species (or a population of a species).

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10
Q

State the 3 levels of biodiversity.

A

Habitat, species, and genetics.

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11
Q

Name 3 examples of different habitats.

A
  • Meadow
  • Woodland
  • Streams
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12
Q

Define the term “sampling” and explain why it is important.

A

Taking measurements of a limited number of individual organisms present in a particular area.
Sampling can be used to estimate the number of organisms in an area without having to count them all.
Can also be used to measure a particular characteristic of an organism e.g. the height plants.

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13
Q

State the two general ways in which sampling can be undertaken.

A
  • Random sampling.

- Non-random.

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14
Q

Define the terms “random sampling”.

A

Studying a representative sample of organisms in their natural habitat. Each organism has an equal chance of being selected.

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15
Q

Define the term “non-random sampling”.

A

The sample of organisms is not chosen at random, it can be opportunistic or stratified, or systematic. Some organisms have more chance than others of being selected for the sample.

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16
Q

Outline how to randomly sample an area.

A

Random sampling uses a quadrat.

  1. Mark out a grid with xy axises on the area you are sampling and choose random co-ordinates from this grid.
  2. Place the quadrat according to the first set of co-ordinates.
  3. Use an identification key to identify the species present within the quadrat.
  4. Record identified species and th abundance of each species in a suitable table and repeat until enough data is collected to calculate a reasonable estimation of the population size of each species within the area.
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17
Q

Name and describe the 3 main techniques of non-random sampling.

A

Opportunistic sampling - Samples whatever organisms are conveniently available. Weakest form as it is not always representative of the population.

Stratified sampling - some populations can be divided into a number of strata (subgroups) based on their characteristics. A random sample is then taken from each of these strata proportional to its size.

Systematic sampling - different areas within an overall habitat are identified which are then sampled separately.

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18
Q

Define the term “frame quadrat”.

A

A square rigid structure of a fixed size used to identify an area to be sampled, it is usually divided into a grid of equal sections.

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19
Q

Define the term “point quadrat”.

A

A horizontal bar set at intervals with 10 long pins, which can be lowered to the ground to take a sample. Every species that the pins touch is recorded as present for that particular sample.

This method uses the ACFOR scale to measure the abundance of each species.

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20
Q

Define “line transect”.

A

This involves marking out a line along the ground between two poles and taking samples at specified points.

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21
Q

Define the term “belt transect”.

A

Two parallel lines are marked and samples are taken from the area between the two lines. Provides more information than the line transect.

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22
Q

Define the term “interrupted belt transect”.

A

Uses a frame quadrat at specific intervals along a line transect.

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23
Q

Explain when random sampling would be appropriate and when systematic sampling would be appropriate.

A

Systematic sampling would be more useful in very big habitats, as it takes samples from different areas within an overall habitat. Would be more representative of the species diversity
Random sampling would be more appropriate for a smaller habitat.
(?????)

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24
Q

Describe five ways to sample animals.

A
  • A pooter, used to catch small insects by sucking on a mouthpiece which draws insects into a holding chamber via an inlet tube.
  • Sweep nets, used to capture insects in long grass.
  • Pitfall traps, used to catch small crawling invertebrates in a whole which is dug in the ground. Must be deep and covered with a roof structure to prevent drowning.
  • Tree beating, a large white cloth is stretched out under the tree. The tree is shaken or beaten to dislodge invertebrates.
  • Kick sampling, the river bank and bed is kicked for a period of time to disturb the substrate. The net is held downstream for a set period of time in order to capture any organisms released into the flowing water.
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25
Q

Describe 2 ways to sample plants (and sessile, or very slow moving, animals).

A

A point quadrat and a frame quadrat.

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26
Q

Describe 3 ways of collecting data using a frame quadrat (that could be applied to either random or non-random sampling).

A
  • Density, count the number of plants in a quadrat which will give you density per square meter. This is an absolute measure, not an estimate.
  • Frequency, individuals members of a species are hard to count (grass), so using small grids within a quadrat count the number of squares a particular species is present in.
  • Percentage cover, this is for speed as lots of data can be collected when a particular species is abundant or difficult to count. An estimate by eye of the area within a quadrat which a species covers.
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27
Q

Define the term “abiotic factor”

A

non-living conditions in a habitat

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28
Q

Define the terms “biotic factor”

A

The living components of an ecosystem.

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29
Q

Name, and state the equipment used to measure, 6 abiotic factors that could be measured when studying the abundance and distribution of organisms in an area.

A
  • Wind speed: anemometer (m/s)
  • Light intensity: lightmeter (lx)
  • Relative humidity: measured with a humidity sensor (dm-3)
  • PH: ph probe (PH)
  • Temperature: temperature probe (degrees c)
  • Oxygen content in water: dissolved oxygen probs (mgdm-3)
30
Q

Explain why a temperature probe linked to a data-logger may be advantageous over the use of a thermometer when investigating factors affecting the abundance and distribution of organisms in an area.

A
  • Rapid changes in temp can be detected.
  • Human error in taking measurements is reduced.
  • A high degree is precision can often be obtained.
  • Data can be stored and tracked.
31
Q

Name and describe 2 ways of measuring species biodiversity.

A
  • counting the number of species present, species richness. This does not take into account the number of individuals present.
  • Simpson’s index of diversity. Takes into account both species richness and species evenness. Better method.
32
Q

State the information needed to determine the species richness and species evenness of an area.

A
  • The number of organisms in one particular species (n).
  • The total number of organisms across all species present (N).
  • The sum of (n/N)2 for that habitat i.e. (n/N)2 calculated individually for each organism present and then all those values added together.
33
Q

Suggest how the population size of plants can be estimated.

A

Using a quadrat and Simpson’s index of diversity.

34
Q

Suggest how the population size of animals can be estimated.

A

Using a variety of sampling techniques (e.g. quadrat) to obtain values for Simpson’s index.

35
Q

Explain why measuring species diversity allows us to obtain information about the stability of an ecosystem or the degree of pollution in an ecosystem.

A

The biodiversity of an area is proportional to its ‘stability’. Stability means an ecosystem’s ability to cope with change. When an environment is very diverse, it has many different species occupying very different ecological niches. This means when there is a change to conditions (i.e. a rise in temp or introduction of a pathogen) some species will suffer but others will continue to thrive. This means the ecosystem will not be too badly damaged, therefore it remains stable (high biodiversity = high level of stability).

Low species diversity would indicate a very unstable environment because a change in conditions could adversely effect all of the species present.

Low species diversity could also indicate high levels of pollution. Harsh conditions created by pollution means only a few highly adapted species could survive.

36
Q

Name one measure of species diversity that takes into account both species richness and species evenness.

A

Simpson’s index of diversity.

37
Q

Describe the meaning of each of the symbols in the equation for calculating Simpson’s index of diversity.

A

E the shaped thing = sum of
N = total number of all organisms
n = total number of organisms in one species.
D = diversity index.

38
Q

Describe the range of values that Simpson’s index of diversity can take and explain how to interpret the value calculated.

A

0 - 1. The closer the index is to 1, the more diverse the habitat and the greater its ability to cope with change.

39
Q

Draw a table to show typical habitat features for areas with low and high biodiversity.
(5 key points of comparison)

A

High biodiversity:

  • large number of sucessful species.
  • relatively benign and unstressful environment with ecological niches.
  • many species with few specific adaptions to the environment
  • complex food webs
  • effect of change to the environment is often a relatively small effect.

Low biodiversity:

  • small number of successful species
  • Harsh conditions
  • Species that live there have very specific adaptations to habitat.
  • simple food webs
  • change can have drastic effects.
40
Q

Explain why a greater genetic biodiversity increases a species chances of long-term survival.

A

Species that contain greater genetic biodiversity are likely to be able to adapt to changes in their environment. This is because there are likely to be some organisms within the population that carry an advantageous allele which enables them to survive in the altered conditions.

41
Q

Name and describe the two ways in which the genetic biodiversity of a population can be increased.

A
  • Mutation in the DNA of an organism creating a new allele.
  • Interbreeding between different populations when an individual migrates and breeds with a member of another population alleles are transferred between the two populations.
42
Q

Describe 6 factors that may cause a decrease in genetic diversity.

A
  • Selective breeding
  • Captive breeding programs, a small number of captive individuals of a species are available for breeding.
  • artificial cloning, asexual reproduction, using cuttings to clone a farmed plant.
  • Natural selection, species evolve to contain the alleles which code for advantageous characteristics.
  • Genetic bottlenecks, where few individuals within a population survive an event or change, thus reducing the gene pool.
  • Founder effect, a small number of individuals create a new colony geographically isolated from the original.
  • Genetic drift, due to the random nature of alleles being passed on from parents to offspring. Sometimes a particular allele can disappear from a population.
43
Q

Define the term “polymorphic”.

A

A gene with more than two possible alleles.

44
Q

Define the term “locus”.

A

The locus of a gene refers to the position of a gene on the chromosome.

45
Q

Write an equation that provides a measure of genetic diversity.

A

To measure polymorphism - genes that aren’t polymorphic are said to be monomorphic. This means a single allele exists for this gene. This ensures the basic structure within individuals within a species remains consistent.
Equations:
The proportion of polymorphic gene loci = number of polymorphic gene loci / total number of gene loci.

46
Q

Describe the range of values that the “proportion of polymorphic gene loci” can take and explain how to interpret the value calculated.

A

0 -1.
The higher the number the greater the proportion of polymorphic gene loci and the greater the proportion of genetic diversity within a gene loci.

47
Q

Describe the change in the human population since 1800.

A

The population now is over 7 times more than in 1800, and over double what it was in 1960s.

48
Q

Describe 3 main issues for biodiversity that have come about due to an increased human population size.

A
  • Deforestation.
  • Agriculture, in many cases planted with a single crop, which is monoculture.
  • Climate change.
49
Q

Describe 4 ways in which deforestation affects biodiversity.

A
  • REDUCES THE NUMBER OF TREES.
  • Destroys habitats, this, in turn, removes other animals food sources. Animals are forced to migrate to other areas, biodiversity of neighboring areas may increase.
50
Q

Describe 5 methods associated with agriculture which affect biodiversity. (F)

A
  • Agriculture causes deforestation.
  • Removal of hedgerows, enables them to use large machinery and frees up land. This reduces the number of plant species present in an area and destroys habitats.
  • Use of chemicals such as pesticides and herbicides. Kills pests which reduces species diversity directly and indirectly.
  • Many farms specialize in the production of only one crop, this is called monoculutre. Reduces species species diversity.
51
Q

Define the term “global warming”.

A

Rising in the earth’s mean surface temperature.

52
Q

Define the term “climate change”.

A

The change in global and regional climate patterns - attributed to fossil fuels.

53
Q

Describe the evidence for climate change and the role of human activities in climate change.

A
  • The warming trend over the last 50 years is nearly twice that for the previous 100.
  • The average amount of water vapour in the atmospere has increased over land and ocean, because warmer air can hold extra water vapour.
  • Global average sea level has risen a lot.
  • Average temperature of oceans has increased.
  • Mountain cover and snow glaciers have decline on average.
  • Upward trend in the amount of precipitation.
54
Q

Describe 4 ways in which biodiversity may be affected by climate change.

A
  • Melting of ice polar caps can lead to extinction of the few plants and animals living in these regions.
  • Rising sea levels could flood low-lying lands reducing the availability of habitats.
  • Higher temps and less rain fall would result in some plant species failing to survive leading to the domination of other plant species.
  • Insect life cycles and populations will change as they adapt to climate change. As insects are key pollinators of many plants this could affect the lives of plants causing extinction.
55
Q

State the 3 categories of reasons for maintaining biodiversity.

A
  • aesthetic
  • economic
  • ecological
56
Q

Describe 3 aesthetic reasons for maintaining biodiversity.

A
  • The presence of different plants and animals in our environment enriches our lives.
  • The natural provides creative inspiration.
  • Studies have shown that patients recover more rapidly when in a relatively natural environment.
57
Q

Describe 8 economic reasons for maintaining biodiversity.

A
  1. Soil erosion and desertification may occur as a result of deforestation- reduce a country’s ability to grow crops and feed its people which can lead to resource ad economic dependence on other nations
  2. Non-sustainable removal of resources will eventually lead to the collapse of industry in an area. Once the raw material has been lost it is not economically viable to continue the industry.
  3. Large-scale habitat and biodiversity losses mean that species with potential economic importance may become extinct before they are discovered.
  4. Continuous monoculture results in soil depletion- a reduction in the diversity of soil nutrients. This makes the crop support weaker, increasing vulnerability to opportunistic insects, plant competitors and microorganisms. Farmer will become dependent on expensive pesticides, fertilisers etc.
  5. High biodiversity provides protection against abiotic stress. When not maintained a change in conditions or a disease can destroy entire crops.
  6. High bio diverse places can promote tourism in the region.
  7. The greater the diversity of an ecosystem, the greater the potential for the manufacture of different products in the future.
  8. Plant varieties are needed for cross-breeding which can lead to better characteristics such as disease resistance. Wild relatives of cultivated crop plants provide genetic material to aid the production of new varieties of crops.
58
Q

Define the term “keystone species” and explain why they are important in maintaining biodiversity.

A

Species which are essential for maintaining biodiversity- they have a disproportionately large effect on their environment relative to their abundance.
e.g. Sea stars eat mussels and sea urchins, which have no other natural predators. If the sea star was removed from the ecosystem, the mussel undergoes a population explosion, reducing the number of other species in the area as they compete for space and other resources.

59
Q

Describe 2 ecological reasons for maintaining biodiversity.

A
  1. All organisms are interdependent on others for survival. The removal of one may have a significant effect on others, for example a food source or a place to live may be lost. e.g plants rely on bees for pollination, declining bee population would decrease crop yield.
  2. Keystone species affect many other organisms in an ecosystem and help to determine the species richness and evenness in the community. When removed the habitat is drastically changed- other species are affected and some may disappear altogether.
60
Q

Define the term conservation`

A

Is the maintenance of biodiversity by preservation and careful management of the environment and of natural resources.

61
Q

Describe the difference between in situ and ex situ conservation

A

in situ- within the natural habitat

ex situ- out of the natural habitat

62
Q

Name 2 methods of in situ conservation.

A

Wildlife reserves

Marine conservation zones

63
Q

Describe 7 methods of active management in wildlife reserves.

A
  1. Controlled grazing- only allow livestock to graze a particular area of land for a certain period of time to allow species time to recover.
  2. Restricting human access- providing paths so plants aren’t trampled etc.
  3. Controlling poaching- creating defences to prevent access, issuing fines etc.
  4. Feeding animals- help to ensure more organisms survive to reproductive age
  5. Reintroduction of species- adding species to areas that have become locally extinct, or whose numbers have decreased rapidly.
  6. Culling or removal of invasive species- invasive species are not native and have negative effects on the economy, environment or health. They compete with native species for resources.
  7. Halting succession- protect habitat such as heath from becoming woodland through controlled grazing.
64
Q

Describe the role of marine conservation zones in maintaining biodiversity.

A
  1. Purpose is to create areas of refuge withing which populations can build-up and repopulate adjacent areas.
  2. Vital in preserving species-rich areas such as coral reefs which are being devastated by non-sustainable fishing methods.
  3. Large areas of sea are required for marine reserve as the target species often move large distances or breed in geographically different areas.
65
Q

Name 3 methods of ex situ conservation.

A
  1. Botanic gardens
  2. Seed banks
  3. Captive breeding programmes
66
Q

Describe the role of botanic gardens in maintaining biodiversity.
4. These wild species are a potential source of genes, conferring resistance to diseases, pests and parasites

A
  1. Plant species can be grown successfully as they are actively managed to provide them with the best resources to grow.
  2. Such as the provision of soil nutrients, sufficient watering and the removal or prevention of pests
  3. But many wild relatives of selectively bred crop species are under-represented amongst the conserved species.
67
Q

Describe the role of seed banks in maintaining biodiversity.

A
  1. An example of a gene bank.
  2. Seeds are carefully stored so that new plants may be grown in the future.
  3. They are stored at low temperatures to maintain their viability, by slowing down the rate at which they lose their ability to germinate.
  4. Provides back up for the extinction of plants in the wild.
  5. But don’t work for all plants as some seeds die when dried and frozen and most seeds in rain-forest fall into this category.
68
Q

Describe the role of captive breeding programmes in maintaining biodiversity.

A
  1. Produce offspring of species in a human-controlled environment. Often in zoos or aquatic centres.
  2. Several species are now solely represented by animals in captivity.
  3. The aim is to create a stable, healthy population of a species and then gradually reintroduce the species back into its natural habitat.
  4. They provide the animals with shelter, and abundant supply of nutritious food, an absence of predators and veterinary treatment.
69
Q

Describe how captive breeding programmes try to maintain (or increase) genetic diversity.

A
  1. Maintaining genetic diversity within a programme can be difficult- only a small number of breeding partners are available, so problems with inbreeding
    can occur.
  2. An international catalogue is maintained, detailing genealogical data on individuals.
  3. Mating can thus be arranged to ensure the genetic diversity is maximised .
  4. Techniques such as artificial insemination, embryo transfer and long-term cryogenic storage of embryos allow new genetic lines to be introduced without having to transport adults to new locations and do not require the animals’ cooperation
70
Q

Explain why it may not be possible to release some captively bred organisms back into the wild.

A
  1. Diseases- there may be a loss of resistance ot local diseases in captive-bred populations. New diseases might exist in the wild, to which captive animals have yet to develop resistance.
  2. Behaviour- Much behaviour has to be learnt- early stages of reintroduction monkeys starved to death as they had no concept of having to search for food.
  3. Genetic races- The genetic make-up of captive animals can become so different form the original population hat the two populations cannot interbreed
  4. Habitat- in many cases the natural habitat must first be restored to allow captive populations to be reintroduced. If only a small habitat exists it is likely that there are already as many individuals as that habitat can support. Introduction of new individuals can lead to tensions as individuals fight for limited territory and resources such as food.
71
Q

State the full name of the IUCN and outline their role in conservation.

A

International Union for the Conservation of Nature:

  1. assist in securing agreements between nations.
  2. Publish the Red List, detailing the current conservation status of threatened animals. Countries can then work together to conserve these species.
  3. Also involved in establishment of the Convention on International Trade in Endangered Species.
  4. This treaty regulates the international trade of wild plants and animal specimens and their products.
  5. The effort to regulate it requires international cooperation to safeguard certain species form over-exploitation.

Biology (35 decks)

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