Chapter 11 - Biodiversity Flashcards
(118 cards)
1
Q
Define abiotic
A
Non living
2
Q
Define biodiversity
A
Variety of living organisms present in an area
3
Q
Define species
A
Smallest + most specific taxomic group
4
Q
How can biodiversity be assessed
A
o The number and range of different ecosystems and habitats
o The number of species and their relative abundance
o The genetic variation within each species
5
Q
What is habitat diversity
A
• range of different ecosystems or habitats within a particular area or region
6
Q
What is species richness
A
number of species within an ecosystem
7
Q
What is species diversity
A
number of different species in an ecosystems + the evenness of abundance across the different species present
8
Q
What is species evenness
A
evenness of abundance across the different species present
9
Q
What will increase the species diversity
A
greater the number of species in an ecosystem + more evenly distributed the number of individuals from each species
10
Q
How can an ecosystem have a lot of different species but not have a high species diversity
A
some species may be very rare in ecosystem = does not necessarily have high species diversity
11
Q
A more stable ecosystem…
A
high species diversity
12
Q
Why does a low species diversity make an unstable ecosystem
A
If pathogen targets one of the species = whole population could be wiped out + ecosystem collapses
13
Q
What is genetic diversity
A
diversity of alleles and genes in the genome of species
14
Q
How to measure genetic diversity
A
by working out the proportion of genes that have more than one form (allele) + how many possible alleles each gene has
15
Q
Why may there be genetic differences between populations of the same species
A
because the two populations occupy slightly different ranges in their habitat = subject to different selection pressures = affect the allele frequencies in their populations
16
Q
Why is genetic diversity within a single population important
A
help the population adapt to, and survive, changes in the environment
17
Q
Negatives of inbreeding
A
leads to a high proportion of individuals being homozygous (e.g. AA to aa) for many genes, resulting in lower genetic diversity
o This can mean that genetic diseases caused by recessive alleles can become more common in these populations
18
Q
What is sampling
A
a method of investigating the abundance and distribution of species and populations
19
Q
Two types of sampling
A
o Random
o Non-random
20
Q
What is random sampling used for
A
to estimate the distribution and abundance of species
21
Q
What is the distribution of a species
A
how it is spread throughout the ecosystem
22
Q
What is the abundance of a species
A
number of individuals of that species
23
Q
How to carry our random sampling - Quadrats
A
- Use Quadrats
- convert sampling area into grid
- use random number generator = quadrats
- record abundance / percentage cover
24
Q
What are Quadrats used for
A
suitable for sampling plants or slow-moving animals
25
Other methods for sampling
- sweep nets
- pitfall traps
- pooters
- tullgreen funnel
- kick sampling
26
Sweep nets
large, strong nets with a fine material (very small holes) that are used to catch flying insects and insects that live in long grass by sweeping the net back and forth through the grass
27
Pitfall trials
cans or jars that are buried in the ground that are used to catch ground-dwelling (often nocturnal) insects and other invertebrates as they fall into the trap
28
Modification in pitfall
- canopy = stop trap filling with water
- newspaper / leaves = allow smaller insects to hide from predatory ones
29
Pooters
small plastic or glass containers with two tubes sticking out that are used to suck up small insects and other small invertebrates
first tube is placed over the insect and the second tube is used by the scientist to create suction
30
Tullgren funnel
funnels with a light bulb above and a container below that are used to collect invertebrates that live in leaf litter or soil.
leaf litter / soil is placed in the funnel and the light and heat forces the invertebrates to move down until they drop into the container
31
Kick sampling
used to catch freshwater invertebrates living in streams or rivers.
net placed on the stream-bed so that the water is flowing into it and the stream-bed just above the net is kicked
invertebrates are carried by the stream into the net
32
Types of non random sampling
• Opportunistic
• Stratified
• Systematic
33
Opportunistic
• choosing sampling locations based on various non-random factors = most convenient
34
Stratified sampling
• population is divided into subgroups or strata based on certain characteristic.. The subgroups are then sampled in proportion to their size or importance in the population = random within each strata
35
Systematic sampling
• method of sampling where every nth member of a population is selected for inclusion in the sample. The sampling interval or "n" is determined by dividing the population size by the desired sample size = random or non random? = no patterns in the data
36
How to do Quadrats non randomly
Using transects
37
How to use line transects
o Lay out a measuring tape in a straight line across the sample area
o At equal distances along the tape, record the identity of the organisms that touch the line. For example, every 2m
38
How to use belt transects
o Place quadrats at regular intervals along the tape and record the abundance or percentage cover of each species within each quadrat
39
What is species richness
measure of the number of different species within a given area
40
Problem with species richness
can be a misleading indicator of diversity as it does not take into account the number of individuals of each species
41
What is spedier evenness
• measure of the relative abundance of the different species within a given area
42
Why is this an example of the problems with species richness
• In the example above , Area 1 and Area 2 both contain 4 tree species
• However, Area 2 is actually dominated by one species and in fact, one of the species is very rare (only one individual)
• Although the two areas have exactly the same species richness, Area 1 has a higher species evenness (and therefore a higher overall species diversity) than Area 2
43
How to measure species richness
count the number of different species present.
44
How to measure species evenness
count the number of different species present and the number of individuals of each species
45
What is Simpsons index formula
You get in exam
46
What do all the variables mean in Simpsons index
• n = total no. of organisms for a single species
• N = total no. of organisms for all species
47
How to use this formula - careful where the sum of is
o Step 1: First calculate n / N for each species
o Step 2: Square each of these values
o Step 3: Add them together and subtract the total from 1
48
What does it mean if the Simpson index is near 1
indicate high levels of biodiversity
49
What does it mean if the Simpson index is near 0
low levels of biodiversity
50
What can the Value of D (simpsons index) Fall between
0 and 1
51
What is genetic diversity
genetic variation in a species
52
How can individuals in the same species have genetic diversity
same genes at the same loci – but maybe different alleles of each gene
53
What is loci
a specific linear position of a gene on a certain chromosome
54
Define gene pool
comprised of all the alleles of all the genes within a species
55
Why is there genetic differences between populations of SAME species
• Because two populations occupy slightly different ranges in their habitat and so are subject to slightly different selection pressures that affect the allele frequencies in their populations
56
More genetic diversity…
Larger gene pool
57
Why is genetic diversity within a SINGLE population important
creates a larger gene pool which can help the population adapt, and survive changes in the environment
58
How is genetic diversity measure
• using the proportion of polymorphic gene loci (number of loci that have two or more alleles)
• using the proportion of the population that is heterozygous for any specific gene locus
• using allele richness = number of different alleles that exist for each specific gene
59
What is similar about all three ways of testing genetic diversity
ALL 3 – determine whether there are multiple genes at a locus
60
How do you identify the alleles
phenotypes / DNA sequences / protein products
61
What is genetic polymorphism
occurs when there are two or more alleles present at a single loci
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What is the frequency of the rarest allele
frequency greater than 1% or greater than 5%
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What is a monomorphic locus
one that does not have multiple alleles = one allele
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What is a polymorphic locus
one that has multiple alleles
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Frequency of most common allele
frequency less than 95% or 99%
66
What happens if the frequency of an allele is more than 95% or 99%
other allele(s) are extremely rare and likely to disappear
67
The equation for calculating the proportion of polymorphic gene loci (P) is:
P = number of polymorphic gene loci ÷ total number of loci investigated
68
There are many different registered pedigree dog breeds that exist.
A conservationist stated that the degree of inbreeding that has occurred in some of the older breeds could be problematic as it likely reduces genetic diversity.
Scientists investigated 100 gene loci in 2 different breeds. For breed A (the older breed), 59 out of 100 gene loci were found to be polymorphic at the 0.95 level. For breed B, 87 out of 100 gene loci were found to be polymorphic at the 0.95 level.
Calculate P for both breeds and evaluate whether the results support the conservationist's statemen
Step 1: Calculate P for breed A
P = number of polymorphic gene loci ÷ total number of loci investigated
P = 59 ÷ 100
P = 0.59
Step 2: Calculate P for breed B
P = 87 ÷ 100
P = 0.87
Step 3: Determine if results support the statement
The older breed A has a lower P value than breed B. This suggests that it has lower genetic diversity which could be caused by inbreeding. More studies would need to be carried out on a larger number of breeds in order to prove this statement true.
69
Limitations of the proportion of genetic loci measurement
does not illustrate the allele richness of a breed or species
70
What does it mean that the proportion of polymorphic gene loci does not illustrate the allele richness of a breed or species
o A study that looked at different blood proteins in dogs found that all genetic loci were polymorphic, P = 1. However, the number of alleles for each gene locus was not the same, it varied from 2 to 1
71
Factors effecting biodiversity
• Human population growth
• Agriculture = monoculture
• Climate change
72
Why is the human population growing
improved tech = abundance of food = increase birth rate
improved medicine / hygiene = decrease in death rate
73
What is habitat loss
plant and animals completely lose their habitats
74
What is habitat fragmentation
habitats are divided into small areas - populations living within these separated habitat fragments are more likely to suffer from inbreeding or local extinction
75
How is the human population growth destroying biodiversity
Deforestation
Destruction of coral reef = catch fishing
Hunting
76
What is monoculture
farms become more specialised + grow only one type of crop
77
What is bad about monoculture
o support much lower levels of biodiversity
78
What else is bad about agriculture other than monoculture / land space
• Use of fertilisers. / pesticides
79
Why are fertilisers bad
leach into waterways, causing eutrophication, which can lead to the death of many aquatic invertebrate and fish species
80
Why are pesticides bad
o kill insect pests but also kill many non-target species = bees
81
Why does a compromise need to be made in agriculture
Because agriculture has high yield + profit = economically viable
82
How is global warming decreasing biodiversity
causing many species to move towards the poles or to higher altitudes
o increasing atmospheric CO₂
83
Why is increasing atmospheric CO₂ bad
more CO₂ dissolving in seawater, decreasing its pH (known as ocean acidification). This is negatively affecting organisms that require calcium carbonate for shells
84
Why is many species to move towards the poles or to higher altitudes bad
o may not be able to compete with / out-compete species already there = decreased biodiversity
o plants – can’t move or change their distributions fast enough to adapt to increasing temperature and may go extinct
85
What is biodiversity made up of
o Genetic diversity
o Species diversity
o Ecosystem diversity
86
Reasons for maintaining biodiversity
• Ecological – protecting keystone species + maintaining genetic resource
• Economic – reducing soil depletion
• Aesthetic – protecting landscapes
87
What is a keystone species
have a larger impact on the ecosystem than others
88
What happens when a keystone species goes extinct
Ecosystem collapses
89
Example of a keystone species - extra
e.g – Bush elephants
• They graze in a very extreme way, knocking over and eating several species of tree
• This destruction of vegetation actually helps to maintain the ecosystem
• Elephant dung also provides a habitat for many important fungi and insect species
• When elephants were legally hunted for their ivory, their numbers reduced and scientists observed a major negative impact on the savannah
90
Why is maintaining biodiversity good economically
• Making medicines
• Ecotourism – jobs / source of income
• Science + technology
91
Reasons for + explanations table - maintaining biodiversity = no need to memorise common sense just read
92
Endangered
threatened with extinction
93
In situ
conservation carried out in the natural habitat
94
Examples of in situ methods
o National parks / marine parks
95
Ex situ
conservation outside natural habitat
96
Examples of ex situ
o Zoos / botanic gardens / seed banks
97
Characteristics of conserved areas
• Human access restricted
• Agriculture / building = regulated
• Hunting prohibited
• Ecotourism
98
What do zoos do
Captive breeding = so offspring can release into wild
99
Problems with captive breeding
reduce genetic diversity
100
Why are zoos bad
not all zoos can provide adequate habitats
101
What are botanic gardens
Plant zoos
102
What do botanic gardens do
o use cuttings and seeds collected from the wild to establish a population of the endangered species in captivity
103
How to conserve genetic material
Frozen zoos
Seed bank
104
Frozen zoos
store genetic material from animals (eggs, sperm, tissue samples etc) at very low temperatures so that they can be kept for a very long time
105
Seed bank
drying and storing seeds in a temperature controlled environment
106
Conservation methods - table list
107
4 conservation agreements
IUCN
CBD
CITES
CSS
108
IUCN stand for
• International Union for the Conservation of Nature
109
CBD stand for
• Convention on Biological Diversity
110
CITES stand for
Convention on International Trade in Endangered Species of Wild Flora and Fauna
111
CSS stand for
• Countryside Stewardship Scheme
112
IUCN
• Role in assessing the conservation status of animal and plant species
113
CBD - three goals
o The conservation of biological diversity by use of a variety of different conservation methods
o The sustainable use of biological resources
o The fair and equitable sharing of benefits arising from genetic resources
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CITES - aim
to control the trade of endangered species and their associated products
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CITES - categories
o Appendix I : species that are endangered and face the greatest risk of extinction
o Appendix II: species that are not currently endangered or facing extinction, but will be unless trade is closely controlled
o Appendix III: species included at request of the country that is regulating trade of the species and trying to prevent its overexploitation
116
How does CITES conserve
Traducing regulations
117
CSS
1980s = provided funding to farmers + private landowners in England who used environmental management strategies to protect + increase the natural biodiversity on their land
118
ESS
CSS replaced with Environmental Stewardship Scheme = 2005
