IB Biology HL A4.2 Conservation of Biodiversity Questions

Practise IB Biology HL A4.2 with evidence-led questions on biodiversity loss, conservation priorities, ecosystem threats, restoration and sustainability.

Exam points

Distinguish species richness from evenness and calculate Simpson’s reciprocal diversity index from community counts, showing the working.
Interpret Simpson’s reciprocal index together with richness and evenness to compare biodiversity between communities or sampling periods.
Explain how human activity causes biodiversity loss through named species extinction and habitat conversion that removes food, shelter and breeding sites.
Identify human drivers of biodiversity loss and explain how a named invasive alien species can outcompete or disrupt native species.
Compare in situ and ex situ conservation, including reserves, zoos, captive breeding, botanical gardens, seed banks and reintroduction.
Explain active in situ management through protected areas, monitoring, anti-poaching, threat control and reintroduction.
Evaluate biological control using a named target and control organism, including selectivity, ecosystem risk and containment.
Explain reserve biogeography and wildlife corridors using area, edge effects, connectivity, movement and genetic exchange.
Explain how EDGE combines evolutionary distinctiveness with extinction risk to justify conservation priorities.

Covered syllabus points

A4.2.1—Biodiversity definition A4.2.2—Current vs. past biodiversity A4.2.3—Anthropogenic species extinction A4.2.4—Ecosystem loss causes A4.2.5—Evidence for biodiversity crisis A4.2.6—Causes of biodiversity crisis A4.2.7—Conservation approaches A4.2.8—EDGE of Existence programme

[Maximum number: 3]

(a)

Distinguish between in situ and ex situ conservation.

[ 1 ]

(b)

Outline one reason for the extinction of a named animal species.

[ 1 ]

(c)

State one use of the Simpson index in ecology.

[ 1 ]

[Maximum number: 2]

Knowledge of deep-water fish is important for fisheries and marine reserve management. Scientists analysed data from scientific trawls made from 1977 to 1989 (early period) and from 1997 to 2002 (late period). These were at depths from 800 m to 4800 m in the Porcupine Seabight and Porcupine Abyssal Plain area southwest of Ireland. The graphs represent the abundance of fish and the number of species for each of these trawls.

Discuss the evidence in these data for a decline in the biodiversity of fish between the early period and the late period.

no evidence that there are fewer species;
difficult to compare as more trawls in the early period / early period of longer duration than late period;
diversity may have increased from (around) $2000\mathrm{m}$ to $4000\mathrm{m}$ / outliers for greater species diversity are all late period;
not enough details about time of year/duration of trawls.

Accept any other valid argument.
Do not accept answers stating only "not enough data".

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Covered syllabus points

Question 1

Question (a)

Question (b)

Question (c)

Question 2