Chapter 11 Biodiversity 2.0 Flashcards
1
Q
What is biodiversity?
A
The variety of different organisms present within an ecosystem
2
Q
Describe the importance of maintaining biodiversity
A
Essential for maintaining a balanced ecosystem for all organisms in order to survive and reproduce.
3
Q
Describe the importance of measuring biodiveristy
A
This informs scientists of the species which are present in the area, therefore measuring the level of effect any changes to the environment will have on biodiversity.
4
Q
What is habitat biodiveristy?
A
The number of different habitats found within an area.
5
Q
Describe the impact to species biodiversity if habitat biodiversity increases.
A
A greater habitat biodiversity means there will be a greater species biodiversity in the area, as each habitat can support a number of different species.
6
Q
What is species biodiveristy?
A
Species biodiversity refers to the richness and evenness of a species within a particular area.
7
Q
What is Species richness?
A
The number of different species living in a particular area.
8
Q
What is Species evenness?
A
A comparison of the numbers of individuals of each species living in a community
9
Q
What is a community?
A
All the populations of different species within the same habitat
10
Q
What is genetic biodiversity?
A
The variety of genes that make up a species
11
Q
Why can a greater genetic biodiversity be considered advantageous?
A
A greater genetic biodiversity within a species allows for better adaption to changing conditions within an environment. Therefore, more organisms are likely to survive and reproduce.
12
Q
What is sampling?
A
Taking measurements of a limited number of individual organisms present in an particular area.
13
Q
What is sampling used to measure?
A
Sampling provides an estimation of the populations of different species, distribution of a species or measured characteristics throughout the entire species.
14
Q
What are the different types of sampling?
A
Random
Non random
15
Q
What is random sampling?
A
Selecting an individual by chance so each individual in a population has an equal opportunity of being selected.
This is carried out using random number tables or computers, the investigator has no involvement in deciding which organisms are investigated.
16
Q
What is Non random sampling?
A
All organisms have different probabilities of being selected
17
Q
What are the three techniques of Non random sampling?
A
Opportunistic
Stratified
Systematic
18
Q
What is opportunistic non random sampling?
A
Uses organisms that are readily available.
Weakest form of sampling as it is not representative of the population.
19
Q
What is stratified non random sampling?
A
Populations are divided into a number of subgroups based on particular characteristics.
A random sample is then taken from each of these subgroups proportional to its size.
20
Q
What is systematic non random sampling?
A
Different areas within an overall habitat are identified and then sampled separately.
21
Q
How can systematic sampling be carried out?
A
Using a line transect or belt transect
22
Q
How is a line transect used to sample organisms?
A
A line is marked on the ground between two points and samples are taken at specified points.
For example, sampling all the organisms that touch the line or distances of samples away from the line.
23
Q
How is a belt transect used to sample organisms?
A
Two parallel lines are marked and samples are taken in the area between the two lines.
24
Q
Why is a sample never entirely representative of the population?
A
Selection process may be biased and the organisms selected may not be representative of the whole population.
25
How can the reliability of the sample be increased?
Sampling bias can be reduced by using random sampling and the effects of chance can be minimised by using a large sample size.
26
What are the different techniques that can be used to sample animals?
Pooter
Sweep nets
Pitfall traps
Tree beating
Kick sampling
27
Describe the process of sampling using a Pooter
A Pooter is used to catch small insects, by sucking on a mouthpiece insects are drawn into a chamber where they can then be counted.
28
Describe the process of sampling using a sweep net
Sweep nets are used to catch insects in areas of long grass
29
Describe the process of sampling using a pitfall trap
Pitfall traps catch small crawling invertebrates.
A hole is dug into the ground and covered with a roof structure to prevent the trap filling with water.
The trap can then be left overnight so nocturnal species can also be sampled.
30
Describe the process of sampling using tree beating
This is used to sample invertebrates that live in tree or bushes.
A cloth is stretched out underneath the tree and the tree is then shaken to dislodge invertebrates so they fall onto the sheet to be counted.
31
Describe the process of sampling using kick sampling
Kick sampling is used to study organisms living in a river. The river bank and bed is disturbed by kicking up the sediment.
A net is set downstream in order to capture any organisms released into flowing water.
32
What is the technique used to sample plants?
Quadrats
33
What are the different types of sampling quadrats?
Point quadrat
Frame quadrat
34
What is a point quadrat?
A frame containing a horizontal bar.
At set intervals along the bar, long pins are pushed through to the ground.
Each species of plant that touch the pin is recorded.
35
What is a frame quadrat?
A square frame divided into a grid.
The type and number of each species within each section of the quadrat is recorded.
36
What are frame quadrats used to measure?
Samples the population of plants living in a habitat:
-Density of a plant per square meter
-Frequency of a particular species by counting the number of squares where the particular species is present
Eg, 25 squares in a quadrat means each square is 4% of the area studied.
Therefore, if 8 squares contained buttercups the frequency occurrence could be 32%
-Percentage cover- an estimate by eye of the area within a quadrat that a particular plant species covers.
37
Describe how an animal population size can be estimated
Capture-mark-release-capture
Individuals of a species are captured within an area
The organisms are marked and then released back into the community
Time is allowed for organisms to redistribute themselves
Another sample is then collected, the researchers can then compare the number of marked individuals with the number of unmarked individuals to estimate the population size.
38
How can the species evenness of a habitat be measured?
An estimation of the total population of different species should be calculated for a particular habitat.
This is carried out through random sampling.
The species evenness can then be identified by comparing the total number of organisms present.
39
Describe what will be observed when a habitat has a high species evenness
Populations or plants or animals that are similar in population size represent a greater species evenness within a community.
Eg, 50 organisms living in a log consists of:
20 woodlouse, 15 spiders, 15 centipedes meaning the community has a high species evenness.
However, if the 50 insects comprised of just 45 woodlouse, 3 spiders and 2 centipedes then the community has low species evenness.
40
How can the species richness of a habitat be measured?
Random sampling is used to estimate and identify all the species present in a habitat.
A list should be made of all the species present in the habitat so the total number of species then be calculated.
41
Describe what will be observed when a habitat has a high species richness
The higher the number of different species present within a habitat, the greater the species richness.
Eg, tropical rainforest has a high number of different species.
42
What is the limitation of species richness?
Does not take into account the number of individuals within a species.
43
What is Simpsons Index of diversity used to measure?
A measure of biodiversity between 0 and 1 that’s takes into account both species richness and evenness.
44
When calculating Simpson index what does a result closer to 0 represent?
Closer 0 represents less diversity
45
When calculating Simpsons index what does a result closer to 1 represent?
Closer to 1 represents more diversity
46
What is the niche of a species?
It’s role within the environment
47
Compare the habitat features for environments with high and low biodiveristy
Environments with low biodiversity:
-few species
-extreme environments
-few ecological niches
-species have specific adaptions to the environment
-simple food webs
Environments with high biodiversity
-large number of species
-more ecological niches
-benign environments
-species have few adaptions to the environment
-complex food webs
48
Describe and explain the importance of maintaining genetic biodiversity
Species that contain a greater genetic biodiversity are likely to be able to adapt to changes within the environment so are less likely to become extinct.
This is because individuals within the population carry an advantageous allele that enables them to continue to survive and reproduce during altered conditions.
49
What factors can increase genetic biodiversity?
Mutations that create new alleles
Gene flow where two different populations are interbred so alleles are transferred between the two populations
50
What factors can decrease genetic biodiversity?
-Selective breeding- where individuals are selected and bred based on advantageous characteristics
-Captive breeding programmes where only few number of captive species are available for breeding
- Rare species where only a small number of individuals remain and are available for breeding.
-Bottleneck effect
-Founder effect
-Genetic drift
51
What is the Bottle neck effect?
The population size of a species is reduced due to a chance event such as a natural disaster or disease.
This decreases the frequency of alleles in the gene pool.
52
What is the Founder effect?
A few individuals from a population start a new population with a different allele frequency than the original population.
53
What is genetic drift?
The random nature of alleles being inherited means the frequency of the occurrence of the allele varies.
This can result in the allele disappearing from the population altogether.
54
What is a polymorphic gene?
A gene that has more than one allele.
Eg, three different alleles for blood type: A, B, O
55
What is a monomorphic gene?
A single allele exists for this gene
56
How can genetic biodiversity be measured?
By measuring the proportion of polymorphic genes. The greater proportion of polymorphic gene loci, the greater the genetic biodiversity.
57
What is the equation used to measure genetic biodiversity?
Proportion of polymorphic gene loci=
Number of polymorphic gene loci
————————————————-
Total number of loci
58
What is loci?
The position of the gene on a chromosome
59
What factors are affecting biodiversity?
Human population growth
Climate change
Increased use of monoculture in agriculture
60
Describe how human population growth has affected biodiversity
As the human population increases there is a greater need for space and resources.
Therefore, habitats have been removed as a result of deforestation to make space for agriculture, buildings and roads.This decreases habitat diversity.
This also means resources are over exploited as the need for food, water and materials increases.
This decreases genetic and species diversity
Urbanisation results in species being unable to interbreeds reducing genetic diversity.
High amounts of pollutants are also released which can kill species and destroy habitats, reducing biodiversity.
61
Describe how the use of monoculture has affected biodiversity
The use of monoculture means a single variety of crop is grown this decreases biodiversity as only one species of plants is present.
This lowers species diversity as few animals will be supported by a single crop.
Habitat diversity is decreased as areas of land are cleared to make way for large fields
Species diversity is reduced as naturally occurring animals and plants are killed by the use of pesticides and herbicides, therefore also decreasing the amount of available food sources.
62
Describe how climate change has affected biodiveristy
A change in climate could mean that an area that was previously inhabitable becomes uninhabitable, therefore causing an increase or decrease in the range that a species inhabits, changing biodiversity.
Species distributions are changed as populations are forced to migrate to more suitable areas changing biodiversity
Biodiversity will decrease when species become extinct if there is not a suitable habitat for the species to migrate to, if the species is a plant or if the change is to fast.
63
What are the reasons for maintaining biodiversity?
Aesthetic reasons
Economic reasons
Ecological reasons
64
Describe the aesthetic reasons for maintaining biodiversity
Areas rich in biodiversity provide pleasant attractive landscapes that people can enjoy.
The natural environment can provide inspiration to people.
65
Describe the economic reasons for maintaining biodiversity
-Areas rich in biodiversity promote tourism which provide economic support
-The continuous use of monoculture leads to soil depletion as the mineral ions required by the crop become used up and are not replenished, therefore farmers are left having to spend out in fertilisers to artificially replace the nutrients.
-Loss of biodiversity means that species with potential economic importance may become extinct before they are discovered.
-The greater the level of biodiversity, the greater potential to manufacture different products in the future which may be beneficial to humans.
-Important to conserve all organisms that have genetic resources needed for daily produce, this is significant for the global economy.
66
Describe the ecological reasons for maintaining biodiversity
-Protection of Keystone species, this is because all organisms are independent on one another for survival. The removal of one species can have a significant effect on the entire ecosystem.
Eg, disruption of food chains or nutrient cycles
-Maintain genetic resources to provide daily products: food, clothing, frugs, fuel and other materials such as wood, oil and adhesives.
67
What is a keystone species?
A species essential for maintaining biodiversity, they have an effect on the environment relative to their abundance.
68
What are genetic resources?
Any material from an organism containing genes which are considered valuable.
They allow us to adapt to changes in the environment.
69
What is conservation?
The preservation and management of the environment and natural resources
70
What are the two types of conservation?
In situ conservation
Ex situ conservation
71
What is in situ conservation?
The protection of a species in their natural habitat
72
Give examples of methods for in situ conservation
Establishing protected areas that conserve habitats and species by restricting urbanisation, agriculture and industrial development:
-Marine conservation zones
-Wildlife reserves
Controlling or preventing the introduction of species that threaten biodiversity
Protecting a species natural habitat
Promoting a species by protecting food sources or nesting sites
Legally protecting endangered species
Restricting human access
73
Evaluate the use of in situ conservation
Advantage:
-Both the species and the habitat are conserved
Larger population can then be protected and it is less disruptive to the organisms and their habitats
Disadvantage:
-Difficult to control factors that threaten a species such as poaching, predators, disease and climate change.
74
What is ex situ conservation?
Protecting a species by removing part of the population from a threatened habitat and placing them into a new location.
75
Give examples for methods of ex situ conservation
-Seed banks- seeds are frozen and stored without losing their fertility.
Seed banks are useful if natural reserves are destroyed.
-Botanical gardens- grow varieties of rare plants for conservation, research and education.
Endangered and extinct plants in the wild can be grown and reintroduced.
-Breeding programmes in zoos- organisms are bred and then reintroduced into the wild.
-Relocating organisms to safer areas
76
Evaluate the use of ex situ conservation
Advantage
-Protect individual animals in a controlled environment (managing predation and hunting)
-Reintroduce species within a habitat
Disadvantage
-Expensive to create and sustain the environment
-Small number of individuals can be cared for
-Usually less successful in captivity as many species can’t breed successfully or don’t adapt to their new environment.
77
Describe the Convention on International Trade in Endangered Species agreement
CITES is an agreement designed to increase international co operation in regulating the trade of wild and animal specimens and their products.
-All members have agreed to make it illegal to kill endangered species
-Illegal to trade in products made from endangered animals
-Raises awareness of the threats to biodiversity through education
78
Describe the Rio Convention on Biological Diversity agreement
CBD aims to develop international strategies on the conservations of biodiversity and how to use animal and plant resources in a sustainable way
-Agreement on international law that it is everyone’s responsibility to conserve biodiversity
-Provides guidance to governments on how to conserve biodiversity
79
Describe the Countryside Stewardship Scheme agreement
CSS aims to conserve wildlife and biodiversity to improve and extend wildlife habitats by promoting specific management techniques to landowners.
-Regenerate hedgerows
-Leave grassy margins
-Restoring neglected land and conserving historical features
