| Date | November 2018 | Marks available | 3 | Reference code | 18N.3.HL.TZ0.15 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
| Command term | Outline | Question number | 15 | Adapted from | N/A |
Question
The graph shows a theoretical model that divides species into five ecological groups (I to V) related to the degree of tolerance to an increasing pollution gradient.
[Reprinted from Marine Pollution Bulletin, 40, A. Borja, J. Franco and V. Perez, 'A marine biotic index to establish the ecological quality of soft-bottom benthos within European estuarine and coastal environments', pp. 1100–1114, Copyright (2000), with permission from Elsevier. https://www.sciencedirect.com/journal/marine-pollution-bulletin]
The biotic index is calculated using the formula shown.
BI=Σ(ni×ai)N
Identify the group that is most intolerant to pollution.
Deduce the meaning of ni in this formula.
Deduce the meaning of ai in this formula.
Outline how organisms in Group V could be used to measure pollution in an environment.
Markscheme
«group» I ✔
number of individuals of a species ✔
tolerance rating of that species ✔
a. group V organisms «could» contain indicator species ✔
b. group V organisms can survive in polluted environments «while others cannot» ✔
c. they have a high tolerance/BI index
OR
«relative number of» indicator species can be used to calculate the value of a biotic index ✔
d. the more group V present could indicate more pollution ✔
OWTTE
e. absence of group V could indicate a cleaner environment ✔
Examiners report
Syllabus sections
- 17N.3.SL.TZ0.14c: Outline how deforestation can affect the richness of biodiversity in an ecosystem.
- 17N.3.SL.TZ0.14b: State one reason mammals can continue to survive even if they are extinct in the wild.
- 17M.3.SL.TZ1.16a: Calculate the diversity of site C. Working should be shown.
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17N.3.HL.TZ0.14b.i:
State the role of an indicator species.
- 18N.3.SL.TZ0.13b: State the name given to organisms whose presence or absence reflects an environmental condition.
- 18M.3.SL.TZ2.12a: Determine how far from the forest edge an increase in disturbance-adapted beetles would be...
- 20N.3.SL.TZ0.14a.i: Two components of biodiversity are richness and evenness. Deduce which of the two pools was...
- 19M.3.SL.TZ2.12d: State one abiotic factor that could have determined the distribution of barnacles.
-
17N.3.HL.TZ0.14b.ii:
Identify possible approaches to maintain the population of P. sandwichensis.
- 17N.3.SL.TZ0.14a: Calculate how many species are classified as endangered due to hunting and trapping.
- 19N.3.SL.TZ0.15a: State the impact of environmental disturbance on biodiversity.
- 18M.3.SL.TZ1.12b: Analyse the differences in biodiversity seen in the three sites.
- 17M.3.HL.TZ1.15b: Discuss two advantages of ex situ conservation measures.
- 18M.3.SL.TZ2.12b: With respect to the example of disturbance-adapted beetles, explain what is meant by an...
-
17N.3.SL.TZ0.14d:
Explain the impact of plastic waste on Laysan albatrosses (Phoebastria immutabilis).
-
18N.3.SL.TZ0.13a:
State which species could be found in mildly polluted water.
- 20N.3.SL.TZ0.14a.ii: Two components of biodiversity are richness and evenness. Deduce which of the two pools was...
- 17M.3.SL.TZ2.18: Explain the use of indicator species to assess the condition of the environment.
- 18N.3.SL.TZ0.13d: Explain how edge effects can influence biodiversity in a region.
- 17M.3.HL.TZ1.15c: State the two components needed to calculate the biodiversity of an area.
- 17M.3.HL.TZ1.14b: Define indicator species.
- 16N.3.SL.TZ0.14a: Outline the trend in the number of people with malaria during the period when the use of...
- 17M.3.HL.TZ2.15c: When coral is bleached, certain organisms become more common in the ecosystem such as the...
-
16N.3.SL.TZ0.13b:
A calculation of Simpson’s reciprocal index was undertaken on each field with the following results.
Evaluate these results.
-
18M.3.SL.TZ1.12a:
Outline what is meant by the edge effect.
- 18N.3.SL.TZ0.13c: Distinguish between richness and evenness as components of biodiversity.
-
19M.3.SL.TZ2.12a:
Outline how the data could have been obtained.
- 19M.3.SL.TZ1.11a: From the data, identify the depth along the transect where the greatest species richness is...
- 19N.3.HL.TZ0.16a: State one advantage of this in situ conservation method.
- 19N.3.HL.TZ0.15c: Describe the use of indicator species in monitoring environmental change.
- 17M.3.SL.TZ1.16c: Discuss the advantages and disadvantages of in situ conservation methods.
- 18N.3.HL.TZ0.15b.ii: Deduce the meaning of ai in this formula.
- 18N.3.HL.TZ0.15a: Identify the group that is most intolerant to pollution.
- 19M.3.HL.TZ1.16b: Distinguish between ex situ and in situ conservation of endangered species.
-
19M.3.SL.TZ2.12e:
Barnacles are sensitive to pollution. Outline how it might be possible to use these organisms as indicator species.
- 19M.3.SL.TZ2.14b: Explain the likely effects on biodiversity if a forest becomes fragmented.
- 19M.3.SL.TZ2.14a: State two abiotic factors that are increased in the fragmented forest with respect to the...
-
19M.3.SL.TZ2.12c:
E. modestus is an invasive barnacle while the others are native species. Analyse the data to show how it supports this statement.
- 16N.3.SL.TZ0.13a: Compare and contrast the richness and the evenness of the two fields.
-
17M.3.HL.TZ1.14c:
Indicator species may be affected by biomagnification. Discuss biomagnification using a named example of a pollutant.
- 20N.3.SL.TZ0.14b: Calculation of Simpson’s reciprocal diversity index for both rockpools gives the following...
-
20N.3.SL.TZ0.14c:
The graph shows how the number of ant species found on isolated islands near New Guinea depends on the size of the island.
[Source: University of Windsor, The Theory of Island Biogeography. Available at:
http://web2.uwindsor.ca/courses/biology/macisaac/55-437/lecture9.htm.]Explain the relationship between island size and number of ant species.
- 18M.3.SL.TZ2.12c: Outline how reserve size and shape can impact edge effects.
- 19M.3.SL.TZ1.11b: Outline the relationship between Zooxanthellae and reef-building coral reef species.
- 19M.3.SL.TZ1.12: Outline one example of an active management strategy employed in the context of in situ...
-
19M.3.HL.TZ2.17:
Outline a named example of the captive breeding and reintroduction of an endangered animal species.
-
19M.3.SL.TZ2.12b:
Describe the distribution of C. montagui and S. balanoides barnacles in Butter Lump Bay.
- 16N.3.HL.TZ0.16b: Outline how the edge effect can affect diversity in forests.
- 16N.3.HL.TZ0.16c: The number of plants in two fields of approximately the same size was counted. Compare and...
- 17M.3.SL.TZ1.16b: Site A has a higher Simpson’s reciprocal index than Site B showing that its diversity is...
- 19N.3.HL.TZ0.16c: State what a high value of Simpson’s reciprocal index of diversity suggests about an ecosystem.
-
18M.3.HL.TZ1.17b:
Explain biogeographic factors that increase the effectiveness of nature reserves.
- 18N.3.HL.TZ0.15b.i: Deduce the meaning of ni in this formula.
