11 Biodiversity

Question 1

Which three levels can biodiversity be studied at?

Answer 1

• Habitat biodiversity
• Species biodiversity
• Genetic biodiversity

Question 2

What is habitat biodiversity?

Answer 2

Habitat biodiversity refers to the number of habitats found within an area

Question 3

What are the two types of species biodiversity?

Answer 3

Species richness, and species evenness

Question 4

What is species richness?

Answer 4

The number of different species living in a particular area

Question 5

What is species evenness?

Answer 5

evenness of abundance across the different species present

Question 6

What is genetic biodiversity?

Answer 6

Genetic biodiversity refers to the variety of genes that make up a species.
variation between individuals of same species
- measured by polymorphic gene loci/total gene loci

Question 7

What is sampling?

Answer 7

Sampling means taking measurements of a limited number of individual organisms present in a particular area.

Question 8

What is random sampling?

Answer 8

• Random sampling is a sampling technique where individuals are selected by chance.
• Each individual in the population has an equal likelihood of selection.
• To decide which organisms to study, random number tables or computers can be used

Question 9

An example of a random sampling method:

Answer 9

1) Mark out a grid on the grass using two tape measures laid at right angles.
2) Use random numbers to determine the x coordinate and the y coordinate on your grid.
3) Take a sample at each of the coordinate pairs generated.

Question 10

What is non-random sampling?

Answer 10

Non-random sampling is a sampling technique where the sample is not chosen at random.

Question 11

What are the 3 main non-random sampling techniques?

Answer 11

Opportunisitic, systematic, stratified

Question 12

What is opportunistic sampling?

Answer 12

• The weakest form of sampling as it may not be representative of the population.
• It uses organisms that are readily available.

Question 13

What is systematic sampling?

Answer 13

• samples are at fixed intervals , measures changes in distribution along an axis
• Involves a line or belt transect.

Question 14

What is stratified sampling?

Answer 14

Some populations can be divided into a number of strata (sub-groups) based on a particular group.

Question 15

Why is a sample never entirely representative of the organisms present in a habitat?

Answer 15

1) Sampling bias- the selection process might be biased e.g choosing to sample a particular area because it has more flowers. Effects can be reduced by random sampling
2) Chance- the organisms selected might not be representative of the whole population. This can be minimised by using a large sample size.

Question 16

What is a pooter?

Answer 16

• A pooter is used to catch small insects.
• By sucking on a mouthpiece, insects are drawn into the holding chamber via the inlet tube.
• A filter before the mouthpiece prevents them from being sucked into the mouth.

Question 17

What are sweep nets?

Answer 17

Used to catch insects in areas of long grass.

Question 18

What are pitfall traps?

Answer 18

• Pitfall traps are used to catch small crawling invertebrates such as spiders, beetles and slugs.
• A hole is dug into the ground which the insects fall into.
• It is covered with a roof-structure so the trap does not fill with rainwater.

Question 19

What is tree beating?

Answer 19

• Tree beating is used to take samples of the invertebrates living in a tree or bush.
• A large white cloth is stretched out under the tree
• The tree is shaken or beaten to dislodge the invertebrates.
• The animals will fall onto the sheet where they can be collected and studied.

Question 20

What is kick sampling?

Answer 20

• It is used to study the organisms in a river.
• The river bank and bed is ‘kicked’ for a period of time to disturb the habitat.
• A net is held just downstream for a set period of time in order to capture any organisms released into the flowing water.

Question 21

What are the two types of quadrats?

Answer 21

Point quadrat and frame quadrat

Question 22

What is a point quadrat?

Answer 22

• This consists of a frame containing a horiziontal bar.
• At set intervals along the bar, long pins can be pushed through the bar to reach the ground.
• Each species of plant the pin touches is recorded

Question 23

What is a frame quadrat?

Answer 23

• This consists of a square frame divided into a grid of equal sections.
• The type and number of species within each section of the quadrat is recorded.

Question 24

What are abiotic factors?

Answer 24

Abiotic factors are the non-living conditions in a habitat.

Question 25

What is the Simpson's Diversity of Index?

Answer 25

A measure of biodiversity between 0 and 1 that takes into account both species richness and species evenness.

Question 26

What is the formula for Simpson's Diversity of Index?

Answer 26

D= 1- Sum of (n/N)^2

Question 27

For genetic biodiversity to increase, the number of possible alleles in a population must also increase. This can occur through:

Answer 27

- Mutation in the DNA of an organism, creating a new allele | - Interbreeding between different populations - increased in gene flow

Question 28

For genetic biodiversity to decrease, the number of possible alleles in a population must also decrease. This can occur through:

Answer 28

- Selective breeding where only a few individuals are selected for their advantageous characteristics - cloning - captive breeding - Natural selection as species will evolve to contain primarily the alleles which code for advantageous characteristics. Over time, alleles coding for less advantageous characteristics will be lost from population. - Genetic bottlenecks, where few individuals within a population survive an event or change,thus reducing the gene pool - The founder effect, where a small number of individuals create a new colony, geographically isolated from the original. - random genetic drift - random nature of genes being passed on

Question 29

How do we calculate the proportion of polymorphic gene loci?

Answer 29

Number of polymorphic gene loci/ Total number of loci

Question 30

What is conservation?

Answer 30

The preservation and careful management of the environment and of natural resources.

Question 31

What are the main two categories of conservation?

Answer 31

In situ & ex situ conservation

Question 32

What is in situ conservation?

Answer 32

Conserving within the natural habitat | E.g wildlife reserves, marine conservation zones

Question 33

What is ex situ conservation?

Answer 33

Conserving out of the natural habitat | E.g botanic gardens, captive breeding programmes, seed bank

Question 34

What is sustainable development?

Answer 34

Economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs.

Question 35

What are some active management techniques in wildlife reserves?

Answer 35

- Controlled grazing: Only allowing livestock to graze a particular area of land for a certain period of time - Restricting human access - Controlling poaching

Question 36

What does the International Union for the Conservation of Nature (IUCN) do?

Answer 36

- Publishes the Red List at least once a year, detailing current conservation status of endangered animals so countries can work together to conserve the species.

Question 37

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

Answer 37

Its aim is to control the trade of endangered species and their associated products. For example, elephants and their ivory tusks - regulate, monitor and prevent trade of endangered species - prohibit (commercial) trade in wild plants ; allow (some) trade in less endangered , wild species

Question 38

What is the Rio Convention?

Answer 38

Creates agreements between nations - sustainable use of , organisms / habitats / ecosystems for example sustainable fishing - sharing access to scientific knowledge and technology

Question 39

What is the countryside stewardship scheme?

Answer 39

- Farmers are paid governmental payments to enhance and observe the English landscape E.g improving, extending, creating wildlife habitats Restoring neglected land Maintaining the beauty and diversity of the landscape

Question 40

What would we use to test for correlation between two sets of data?

Answer 40

Spearmans rank

Question 41

What would we use to test for significance of difference between two values or means?

Answer 41

T-test

Question 42

What would we use to test for significance of associations between categorical data?

Answer 42

Chi squared

Question 43

Outline the significance of a low value of Simpson’s Index of Diversity.

Answer 43

habitat is dominated by one/few species, | change in one species , likely to affect whole habitat thus ecosystem is unstable and less likely to cope with change

Question 44

explain the importance of sampling

Answer 44

counting every individual is too time consuming and difficult, sampling provides an estimate and is representative of whole area

Question 45

Explain why it is sometimes necessary to conserve a plant species outside its natural habitat (ex situ).

Answer 45

(natural) habitat / ecosystem , lost due to / destroyed by / under threat from , climate change / reason natural disaster / deforestation , as reason for habitat loss (named) human activity ; number / population , (in natural habitat) is very low ; (breeding ex situ can) maintain , the gene pool / genetic / allelic , diversity allows protection from , grazers / herbivores / plant collectors / competing species ; ora protection from , predators / poachers / hunters idea of protection from pathogen / parasites / disease

Question 46

Give three advantages of conserving plant species as seeds and not as adult plants.

Answer 46

less , susceptible / vulnerable , to, disease / pests / environmental change take up little space / larger numbers can be stored ow(er) maintenance / manpower costs, less labour-intensive can be collected with minimal damage to (wild) , population / habitat / ecosystem

Question 47

Outline an unbiased sampling method that can be used to measure the biodiversity of plant species in grassland.

Answer 47

use frame quadrat place measuring tapes at right angles randomly generate coordinates using a number generator and place quadrants at coordinates repeat many times sample at different , seasons / times of year

Question 48

Scientists try to estimate the total number of species on Earth. Suggest three reasons why such estimates are not likely to be accurate.

Answer 48

reason for not having found all species may have become extinct , recently / since recording ; evolution is on-going / new species are being formed species can be difficult to distinguish - might mistake several species for one

Question 49

define biodiversity

Answer 49

range / variety / number , of species (in an area) | range / variety of, habitats / ecosystems ; variety of , alleles / genes

Question 50

sampling animals

Answer 50

- pit fall traps - pooter - sweep nets - catch and release recapture method with live animals

Question 51

catch and release recapture method and formula

Answer 51

``` catch , mark them , then second catch and see how many have marks on them formula : C1 X C2 / CM c1= fist capture c2= second capture cM = marked number in second capture ```

Question 52

The proportion of polymorphic gene loci is the

Answer 52

The number of loci that have two or more alleles

Question 53

why is genetic diversity important within a population

Answer 53

Diversity in a species is important as it creates a larger gene pool which can help the population adapt, and survive changes in the environment The changes could be biotic factors such as new predators, pathogens and competition with other species or they could be abiotic factors like temperature, humidity and rainfall

Question 54

factors affecting biodiversity :

Answer 54

human population growth agriculture (monoculture) climate change

Question 55

human population growth

Answer 55

The global human population has been growing exponentially There are many reasons for this exponential growth, including: Improved technology leading to an abundance of food = increase in birth rate Improved medicine, hygiene and health care = decrease in death rate ``` The main factors affecting biodiversity today are: Habitat destruction Overexploitation Hunting Agriculture Climate change ```

Question 56

process of selective breeding

Answer 56

select male an female with desired characteristic mate them together so they reproduce, select the best offsprings, breeding the best offsprings together - process id repeated, breeding (and selecting) for , many / several

Question 57

Suggest how organic fertilisers improve the yield of plant crops

Answer 57

broken down by, decomposers / bacteria / fungi ; add (named) mineral(s) to soil ; nitrate and phosphate and potassium lack of (named) , mineral(s) / nutrient(s) / ion(s), is limiting factor for growth organic fertilisers improve the soil quality in this way

Question 58

overuse of fertiliser leads to reduced biodiversity

Answer 58

- might change soil pH so some plants can’t grow, reduces soil quietly over time so plants cannot grow - (fertiliser) promotes growth of, one / few, (plant) species other (plant) species , out-competed

Question 59

Explain why a reduction in biodiversity may present problems for agriculture in the future.

Answer 59

- loss of genetic , diversity / variation (in wild population) - - environment / agricultural requirements, may change (in future) ; (lost) genes / alleles , may have been useful ; e. g. of gene useful to agriculture like gene resistance to disease

Question 60

Suggest why it is important to ensure that, for each species, the seeds in a seed bank have been collected from several different sites in the wild.

Answer 60

maintain / increase) genetic variation / gene pool ; reduced chance of (future), disease / environmental change, affecting (whole) population ; reduces chance of inbreeding ; maintain, geographical variation

Question 61

Aphids can be killed using an insecticide. However, over a period of time, an increasing concentration of insecticide is required to control the aphid population. Explain why this is the case

Answer 61

natural selection process - insecticide is the , selective agent / selection pressure ; mutation in genes are randomly occurring the ones with the mutation that is resistant to insecticide survive / non-resistant die ; (resistants will) pass on , allele / mutation , for resistance (to offspring) higher proportion of / more , resistant individuals in population

Question 62

Suggest two factors to be taken into consideration when selecting individuals for this breeding programme

Answer 62

healthy/fertile individuals of reproductive age unrelated individuals, ensure they are sufficiently genetically different

Question 63

Finally, a captive bred female Spix’s Macaw was released into the original male’s territory. What could be done to try to ensure the success of this release programme?

Answer 63

birds are healthy before release (quarantine before release) method to monitor the population (for example tag them) method to prepare animals for survival in wild - raise with minimal contact from humans, eg: allow them to find own food raise public awareness / educate local population protected reserve / no hunting / no poaching

Question 64

why ex situ over in situ ?

Answer 64

fed uncontaminated food health of individuals monitored / treated for disease reduced mortality of young ; mate / females breeding can be manipulated ; protection , from hunting / predation ; competition reduced (between , individuals / species