Biodiversity

Question 1

Explain the importance of sampling in measuring the biodiversity of a habitat? (2)

Answer 1

(1) impossible to count every individual
(2) sample provides an estimate
(3) sample representative (of whole area)

Question 2

Why is it important to take samples in fenced and unfenced areas (in two areas)? (1)

Answer 2

(1) to compare (the two areas) (2) independent variable (3) one acts as controlled

Question 3

Explain the difference between species richness and species evenness and why both measurements are needed to assess biodiversity? (3)

Answer 3

(1) species richness is the number of species (in a habitat) (2) species evenness is abundance of each species (3) both are needed to revel dominance (4) high biodiversity associated with high species richness and high species evenness

Question 4

Outline the significance of a low value of simpons index of diversity? (2)

Answer 4

(1) habitat dominated by a few species (2) ecosystem is unstable (3) change in one species (is) likely to affect (the) whole habitat

Question 5

suggest advantages why conserving plant species as seeds and not as adult plants? (3)

Answer 5

(1) it can be collected with minimal damage to habitat (2) take up little space (3) can store greater diversity (4) lower maintenance (6) kept dry so they do not rot (5) easy to transport

Question 6

give reasons why it’s important to conserve animals? (3)

Answer 6

(1) right to exist/ duty of humans to care for other species (2) beautiful creatures (3) tourism/ might provide a useful resource

Question 7

give reasons why estimates are not likely to accurate? (3)

Answer 7

(!) some habitats are rare (2) may have been distinct recently (3) evolution is on-going (4) might mistake serval species for one/ difficult to distinguish

Question 8

Explain why it is sometimes necessary to conserve a plant species outside its natural habitat (ex situ)? (3)

Answer 8

(1) habitat lost due to climate change (2) population is very low (3) allows protection from competing species (4) reproduction is difficult/ maintain the genetic diversity

Question 9

outline an unbiased sampling method that can be used to measure the biodiversity of plant species(in grassland)? (4 marks)

Answer 9

(1) use of quadrat (2) random selection of, areas (3) placing measuring tapes (at right angles) (4) use of transect (5) quadrat placed at regular intervals (6) use of identification key (7)percentage cover used to determine abundance (8) repeat many times (9) sample at different seasons

Question 10

suggest steps that ensure simpons index of diversity is accurate as possible? (2 marks)

Answer 10

(1) idea of random sampling (2)survey at different times of the year

Question 11

define the term biodiversity? (2 marks)

Answer 11

(1) range of species (in an area) (2) range of habitat (3) variety of gene

Question 12

suggest reasons why it’s important to conserve animals? (2 marks)

Answer 12

(1) part of food chain (2) tourism (3) native species

Question 13

state 3 criteria that would have to considered when the EIA (environmental impact assessment) is being carried out (on building)? (3 marks)

Answer 13

(1) size/ “how big will it be?” (2) “what lives there?”/”the biodiversity of the area?” (3) potential damage/ “how much damage will it do?” (4) “what can be done about it?”

Question 14

suggest why the number of species estimated is likely to be lower than the actual number of species? (2marks)

Answer 14

(1) not all areas explored (2) small species are diffcult to see (3) sampling may miss rare species

Question 15

aims of convection on internnational trade in endangered in endangered species (CITES)? (2 marks)

Answer 15

(1) regulate trade in endagered species (2) ensuring trade does not put wild populations at risk (3) prohibiting commercial trade in wild plants (4) allowing trade in less endangered species

Question 16

aims of rio convection on biological diversity? ( 2 marks)

Answer 16

(1) share gentic resources (2) share access to scientific knowledge (3) set up seed bank (4) take biodiversity into account during planning processes (5) informing people that it is their duty to consider biodiversity

Question 17

explain why a reduction in biodiversity may present problems for argiculture in the future? (3 marks)

Answer 17

(1) loss of gentic diversity (2) argiculture reqirments may change (3) lost gene may have been useful (4)e.g gene for heat tolerance (6) loss of predators (5) fewer pollinators

Question 18

definition of random?

Answer 18

sampling in which the observer does not decide when and where to take measurements

Question 19

definition of sample?

Answer 19

a representative of organisms that are selected from a population

Question 20

definition of habitat?

Answer 20

an area in which an organism lives

Question 21

definition of abundance?

Answer 21

the frequency of occurrence of plants in a paritcular area

Question 22

what is ex-situ?

Answer 22

conservation of species not in their natural habitat

Question 23

why is it important to ensure that for each species the seeds in a seed bank are collected from serval different sites in the wild? (3 marks)

Answer 23

(1) genetic variation (2) reduced chance of diseases affecting whole population (3) reduces change of interbreeding (4) maintain varieties

Question 24

Explain why eggs produced by 2 diffrent species mating did not hatch? (2 marks)

Answer 24

(1) different species ; (2) different genus ; (3) genetically incompatible ; (4) (may have) different number of chromosomes ; (5) eggs remain unfertilised

Question 25

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? (3 marks)

Answer 25

(1) bird(s) healthy before release ; (2) protected reserve (3) raise public awareness (4) raise with minimal human contact, predat awareness training

Question 26

The insects were sampled using a sweep net method. Describe three ways in which the sampling procedure could be designed to try to make sure that a representative sample was obtained? (3 marks)

Answer 26

(1) random selection of areas OR use of transect (2) sample many times (3) sample at same time of day (4) ensure insects do not escape (before being identified) (5) mark-release-recapture

Question 27

Explain the importance of species evenness in determining the biodiversity in a habitat. (3 marks)

Answer 27

(1) (measures) abundance of individuals in each species (2) species evenness is more quantitative than species richness (3) high(er) species evenness indicates high(er) biodiversity (4) low species evenness indicates high abundance of one species (5) used to calculate (Simpson’s) Index of Diversity

Question 28

Suggest the implications of a high value of Simpson’s Index of Diversity on planning decisions. (2 marks)

Answer 28

(1) many species present / high biodiversity ; (2) (so) should not be developed or should be modified

Question 29

Suggest what is meant by critically endangered.

Answer 29

likely to become extinct

Question 30

Explain why the decision was made to conserve the species in captivity (ex situ) rather than in the wild (in situ). (4 marks)

Answer 30

in captivity – fed uncontaminated food / keep away from painkiller ; health of individuals monitored / treated for disease ; eggs (artificially) incubated / young hand reared ; reduced mortality of young ; provision of mate / females breeding can be manipulated ; protection , from hunting / predation ; competition reduced (between , individuals / species)

Question 31

Describe how it is possible to use selective breeding to improve the overall disease resistance of a crop, such as potatoes, in both the short and long term? (7 marks)

Answer 31

1) make two disease resistant individuals reproduce 2) e.g: ‘germinate seeds, expose to disease, see if die 3) select best offspring 4) (inter)breed best offspring 5) (continue process) for (many) generations 6) avoid breeding closely related individuals to preserve genetic diversity 7)use of seed bank to preserve range of alleles