IB ESS HL 3.1 Biodiversity and Evolution Questions

Practise IB ESS HL 3.1 by analysing diversity indices and evidence for natural selection, isolation and speciation.

Exam points

Analyse habitat, species and genetic diversity using richness, evenness and abundance data.
Evaluate natural selection from heritable variation, selection pressure and differential reproduction.
Analyse speciation through isolation, divergent selection and loss of fertile reproduction.
Calculate and interpret Simpson’s reciprocal index, including limitations of sampling evidence.

Covered syllabus points

3.1.1—Biodiversity levels 3.1.2—Diversity and resilience 3.1.3—Biodiversity from evolution 3.1.4—Natural selection 3.1.5—Natural selection process 3.1.6—Speciation 3.1.7—Species diversity components 3.1.8—Simpson's reciprocal index 3.1.9—Biodiversity knowledge for conservation 3.1.10 (HL)—Sources of genetic diversity 3.1.11 (HL)—Reproductive isolation 3.1.12 (HL)—Biodiversity hotspots 3.1.13 (HL)—Human-driven selection 3.1.14 (HL)—Artificial selection and resilience 3.1.15 (HL)—Earth history and evolution 3.1.16 (HL)—Geological epochs 3.1.17 (HL)—Mass extinction and speciation 3.1.18 (HL)—Anthropocene debate 3.1.19 (HL)—Human impacts in geological record

[Maximum number: 1]

Figure 1(a): Extinction risk levels of species in global biodiversity by category

Figure:Extinction risk levels of species in global biodiversity by category

Figure 1(b): Changing species extinction risk by category 1980–2015

Figure:Changing species extinction risk by category 1980–2015

Figures 1(a) and 1(b) are based on records for species diversity. Identify one other factor that may be measured to assess the diversity of life on Earth.

[Maximum number: 11]

(a)

Outline the mechanisms by which a terrestrial species may have evolved from an aquatic ancestor.

[ 4 ]

(b)

Explain the ways in which species diversity and an abundance of plant and herbivore species will increase the resilience of an ecosystem.

[ 7 ]

[Maximum number: 7]

Explain one natural and one human-caused factor that influences changes in biodiversity.

[Maximum number: 7]

Explain the ways in which species diversity and an abundance of plant and herbivore species will increase the resilience of an ecosystem.

[Maximum number: 2]

Figure:Continents and species diversity over time

Outline the role of natural selection in increasing the diversity of species.

[Maximum number: 2]

Figure:Fact file on Mindo cloud forest

Figure:Fact file on Mindo harlequin toad

There is no cure and those infected experience 85–100% mortality.

Explain how the disease in the Mindo harlequin toad could contribute to the evolution of resistance to this disease in the species for future generations.

[Maximum number: 7]

Explain how natural processes may lead to the formation of new species.

[Maximum number: 2]

Figure:Four species of the family Leporidae

Figure:A dichotomous key for species A to D

Figure:Sagebrush ecosystem without invasive cheatgrass

Figure:Sagebrush ecosystem with invasive cheatgrass

The family Leporidae includes hares and rabbits. The figures show four species that can be found in western North America.

Distinguish between the biodiversity of the sagebrush ecosystems in Figures 1(c) and 1(d).

[Maximum number: 2]

Figure:Eight freshwater organisms

Figure 2 shows eight freshwater organisms.

Table:Organisms sampled in streams A and B

The table shows data from sampling two streams: A and B. Calculate the Simpson’s Diversity Index for Stream B.
$D=\frac{N(N-1)}{\sum n(n-1)}$
You must show your working.

$\frac{150(150-1)}{1(1-1)+4(4-1)+45(45-1)+100(100-1)}$ ;
1.88/1.879/1.9;

Both top and bottom values of equation need to be correct to be credited mark for showing working out.

[Maximum number: 1]

Figure 2(c): Conservation status of indigenous species groups in New Zealand

Figure:Conservation status of indigenous species groups in New Zealand

Suggest one reason why there is insufficient data available to categorise the conservation status of a large proportion of marine mammals, as shown in Figure 2(c).

[Maximum number: 4]

Identify four reasons why the genetic diversity of a population may change over time.

[Maximum number: 2]

Figure:Conservation status of indigenous species groups in New Zealand

Figure 2(b): Proportion of New Zealand species that are endemic

Figure:Proportion of New Zealand species that are endemic

Figure:Fact file on biodiversity in New Zealand

Figure 2(a): Fact file on biodiversity in New Zealand
New Zealand is a geographically isolated island system which became separated from the southern supercontinent 85 million years ago. It has many endemic species, including flightless birds such as Kiwi, Kākāpō and Takahē, which evolved in the absence of terrestrial ground predators.

Outline two factors that may have contributed to the large number of species only found within New Zealand.

[Maximum number: 3]

Explain why Ecuador supports a high level of biodiversity.

[Maximum number: 2]

(a)

Figure:Distribution of two peppered-moth forms

Figure 4 shows the distribution of two forms of peppered moths in woodlands of the UK in the 1950s. At the time, surfaces of most trees in Central and South Eastern England were heavily blackened with deposits of carbon from local coal burning. There are two forms of the moth, dark and light, and both may be eaten by woodland birds.

[ 2 ]

(i)

Describe the relationship between the distribution of the two forms of moths and habitat pollution.

[ 1 ]

(ii)

Suggest one reason to explain the relationship you have identified in (b)(i).

[ 1 ]

[Maximum number: 2]

The graph shows past mass extinctions.

Explain one factor that may make a species less prone to extinction.

[Maximum number: 7]

Explain how the movement of tectonic plates has influenced biodiversity and evolution.

[Maximum number: 2]

The graph shows past mass extinctions.

Identify two ways in which the current extinction differs from mass extinctions in the past.

All question bank results loaded

Covered syllabus points

Question 1

Question 2

Question (a)

Question (b)

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question (a)

Question (i)

Question (ii)

Question 15

Question 16

Question 17