Biology OCR > Biodiversity > Flashcards

Biodiversity Flashcards

(59 cards)

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1
Q

What is a habitat?

A

The place where an organism lives with a specific set of conditions

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2
Q

What is a species?

A

A group of individual organisms that are very similar that are able to produce fertile offspring

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3
Q

What is biodiversity?

A

The variety of living species found in a habitat, ecosystem or world. It includes 3 levels.

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4
Q

What is habitat diversity?

A

The number of different habitats in an area.

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5
Q

What is species diversity?

A

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

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6
Q

What is genetic diversity?

A

The genetic variation of alleles within a species

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7
Q

What is random sampling?

A

The most common way is by setting up a grid system with two tape measures at 90º. You then use a random number generator to work out coordinates to sample. This reduces bias

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8
Q

What is systematic sampling?

A

When samples are taken at fixed I tervals along a line using a belt or line transect. This is suitable for measuring changes across a habitat

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9
Q

What is Stratified sampling?

A

This is used if a habitat contains discrete patches with different types of organisms. We can divide the habitat into different areas and the proportionally place them evenly between the areas.

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10
Q

What is Opportunistic sampling?

A

Where the researcher decides to sample certain areas. E.g if an area is too marshy

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11
Q

What will the sample size depend on?

A

-Size of the habitat
-Time available
-Number of species in the habitat
-Must be representative

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12
Q

How do you estimate biodiversity using samples?

A

1) Choose a site to sample
2) Record the number of species and their abundance
3) Repeat the process so it’s as accurate as possible. All samples should be done in the same way
4) Estimate the size for the whole habitat

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13
Q

What methods can you use to collect animals?

A

-Pitfall traps for small insects
-Pooter
-Sweep net
-Tree beating

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14
Q

What are point quadrats?

A

They are used to record all the species a pin touches as it is lowered through the vegetation. You then calculate abundance as a %.

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15
Q

What is a frame quadrat?

A

A square frame divided into a grid of equal sections.

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16
Q

What should you work out using quadrats?

A

1) Count individual plants
2) Estimate using frequency. E.g if 10 out of 25 squares are covered it is 40% frequency
3) Estimate percentage cover of each species by eye
4) Estimate abundance using a scale like ACFOR however this is qualitative

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17
Q

How do you estimate the size of animal populations?

A

Use the capture, mark, release and recapture method using non toxic dyes. Then use the calculation N1 × N2 ÷ Nm
N1 = size first sample
N2 = size second sample
Nm = number recaptured

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18
Q

What can abiotic factors be measured with?

A

Sensors which measure them with high precision.

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19
Q

Describe how to use simpons index of biodiversity?

A

1 - (Z(n÷N)²)
n = the number of individuals of a certain species
N = the total number of individuals of all species

The index should always be between 1 and 0

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20
Q

What does a high index of diversity suggest?

A

-A diverse habitat
-Many different species living there
-Not dominated by one or two species
-Small change in environment may only affect ine or two species

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21
Q

What is a gene?

A

A section of DNA that codes for the production of a polypeptide

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22
Q

What are different versions of a gene called?

A

Alleles

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23
Q

What are populations where genetic diversity may be low?

A

-Isolated populations
-Zoos
-Rare breeds

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24
Q

What is the loci?

Study These Flashcards
A

The position of a gene in the genome on a chromosome

25
What is the calculation to work out the proportion of polymorphic gene loci?
No. Polymorphic gene loci ÷ total number of loci
26
What is a population bottleneck?
Where population decreases due to a natural disaster so they loose alleles as well. Population then increases but some alleles are still lost
27
Wheb may genetic diversity decrease?
-Selective breeding -Captive programmes -Rare breeds -The founder effect -Cloning -Natural selection -The bottleneck effect -Genetic drift
28
What are the factors affecting biodiversity?
-Disease -Monoculture: Causes loss of heritage plants Causes spil erosion Loss of soil nutrients -Habitat loss for more land -Pollution Causes acid rain -Increased predators due to selection pressures -Climate change: Causes different abiotic factors Also Causes migration
29
What are the Ecological reasons to maintain biodiversity?
1) Protect species: Especially Keystone species as ecosystems would change dramatically without them. Otherwise food chains etc could be affected 2) To maintain genetic resources: Used in industrial processes and medicine. These also allow us to adapt resources to be e.g drought resistant. They provide us with a variety of everyday products
30
What are the economic reasons to maintain biodiversity?
-Soil depletion due to monoculture means it costs money to replace nutrients -Maintain the trade of genetic resources
31
What are the aesthetic reasons to maintain biodiversity?
-Makes landscapes attractive -Can lead to economic advantages -Will attract visitors
32
What does in situ mean?
When endangered species are conserved in their natural habitats
33
What does ex situ mean?
When endangered species are conserved away from their natural habitat
34
What is an endangered species?
A species that is likely to become extinct, or is at risk of becoming extinct
35
What are the examples of in situ conservation?
-Establishing protected areas e.g national parks or reserves -Controlling the introduction of species that threaten local biodiversity -Legislation -Restoring damaged habitats -Promoting particular species -Giving legal protection to endangered species
36
What are the advantages of in situ conservation?
-Species and habitat are conserved -Larger populations can be discovered -Less disruptive -Chances of populations recovering are greater
37
What are the disadvantages of in situ conservation?
-Difficult to control some factors -Difficult to monitor species
38
What are the examples of ex situ conservation?
-Zoos -Seedbanks (seeds frozen without looking their fertility) -Relocations -Breeding in captivity then releasing them -Botanic gardens (controlled environments used to grow rare plants)
39
What are the advantages of ex situ conservation?
-Can protect individual animals -Fa tors can be controlled more easily -Health of individuals can be checked -Breeding can be manipulated
40
What are the disadvantages of ex situ conservation?
-Only a small number of individuals can be cared for -Difficult and expencive to recreate their environment -Human contact may cause them to loose their natural instincts -Catch human disease -Less successful as they cannot breed as easily as they can't adapt to their environment as well
41
What is the CITES agreement?
Stands for thr convention on international trade in endangered species. It is an agreement designed to increase international cooperation in regulating trade in wild animal and plant species.
42
What does the CITES agreement aim to do?
-Regulate the trade of endangered species -Encourage trade that does not endanger species -Permits regulated trade of less endangered species -Allows trade of artificially propagated plants
43
What is the issue with CITES?
International policies are hard to enforce, and it could go the opposite way making species products increase in value
44
What is the RIO convention on biodiversity?
An international agreement dedicated to promoting sustainable development
45
What does the RIO convention aim to do?
-Conservation of genetic diversity -Sustainable use for nature -Shared access for genetic resources -Shared transfer of scientific knowledge and technology -Members using ex situ and in situ conservation -Encourages cooperation between members
46
What are environmental impact assessments?
under the rio convention all members must undertake one. It aims to: -Avoid adverse impacts on environments -Ensure potential environmental impacts are taken into account -Promote international and national exchange of opinions and infomation
47
What is the countryside stewardship scheme?
A local scheme operated until 2014 which offered government payments to farmers and landowners to encourage activities which promoted conservation. E.g: -Maintaining beauty and diversity of landscapes -Creating hedgerows and woodlands to provide habitat -Providing opportunities for people to enjoy the countryside
48
What is the chi squared test?
It is used to compare the expected and observed values to see if there is a significant difference between them.
49
What is the calculation for chi squared?
Z(fo - fe)² ÷ fe Fo = observed value Fe = expected value You expect all the values to be the same
50
What is the unpaired t test?
We use this to compare 2 different sets of the same type of data to see if there is a significant difference in the mean of each. Measurements are not taken from the same individual.
51
How do you carry out the unpaired t test?
Calculate the mean and standard deviation of both sets of data. Use the formula: X̌a - X̌b ÷ _/s²a÷na+s²b÷nb X̌a = mean of data set a X̌b = mean of data set b S²a = standard deviation data a S²b = standard deviation data b Na = no. Samples in set a Nb = no. Samples in set b The degrees of freedom is (n-1) +(n-1)
52
What is the paired t test?
Used when there are two measurements that are collected from the same Individual and we are looking for differences
53
How do we work out the paired t test?
1) work out the difference between each value. 2) Work out the standard deviation of the differences 3) use the formula: Ď_/n÷Sd Ď = mean difference n = no. Paires Sd = standard deviation
54
What is the spearmans rank correlation coefficient?
We use it to see if there is a significant correlation between two sets of data. All Rs values should be between 1 and -1
55
How do you work out spearmans rank correlation coefficient?
Rank both sets of data from lowest to highest. You then work out the difference and square that. Then use the formula: 1- 6Zd² ÷ n(n²-1) d² is the values you just worked out n is the number of pairs
56
How do you work out degrees of freedom for chi squared and the paired t test
-1 from the sets of data
57
How do you work out degrees of freedom for the unpaired t test and
-2 from the sets of data
58
What do you do if the critical value is lower than the value calculated?
We reject the null hypothesis
59
What is the null hypothesis?
Says there is no significant difference between the values
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