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CAIE A-Level Biology A2 18.3 Conservation Questions

Practise conservation by tracing extinction pressures, weighing the value of biodiversity and outlining practical ways to preserve endangered species.

Syllabus
2028–2030
Course
Biology 9700
Level
A2

Exam points

  • Explain how habitat loss, climate change, competition or human hunting can drive extinction risk.
  • Justify conservation through biodiversity's ecosystem, genetic, resource, medical, research and ethical value.
  • Outline zoo and botanic-garden roles in breeding, research, veterinary care and public education.
  • Describe protected-area roles in safeguarding habitats and supporting endangered-species reintroduction.
  • Explain how seed banks and frozen zoos preserve genetic material for future restoration or recovery.
  • Sequence IVF from hormone-stimulated oocyte collection and fertilisation to embryo transfer or surrogacy.
  • Explain how invasive aliens compete, prey on or spread disease to native species, disrupting food webs.
  • Outline IUCN Red List assessment and advice, and how CITES regulates trade through permits or bans.

Covered syllabus points

18.3.1—Extinction causes18.3.2—Reasons to maintain biodiversity18.3.3—Ex situ and protected-area conservation18.3.4—Assisted reproduction in endangered mammals18.3.5—Invasive alien species18.3.6—Conservation organisations

Question 1

[Maximum number: 3]

Measurements of the surface temperature of land and oceans can be taken from locations around the world. The mean global surface temperature for land and ocean combined can be calculated for a fixed time period.
Scientists calculated:
- the mean global temperature for the twentieth century
- the mean global temperature for each decade (ten years) from 1880 to 2020.
The mean temperature for each decade was compared to the mean for the twentieth century. For each decade, the difference in temperature was calculated.
The calculated differences are shown in Fig. 10.2.

Fig. 10.2

Fig. 10.2

Moose populations have decreased in North America since 1980.

Suggest and explain reasons for the decrease in moose populations.

Question 2

[Maximum number: 10]

Question (a)

(a)

Over the past 200 years, many species of animals and plants have become extinct.
Fig. 8.1 shows the changes between the years 1800 and 2000 in:
- the number of species becoming extinct
- the size of the world human population.

number of known extinct species

number of known extinct species

world human population ( ×106\times 10^{6} )

[ 3 ]

Question (i)

(i)

It has been suggested that there is a correlation between the number of species becoming extinct and the size of the world human population.

Suggest reasons for this possible correlation.

[ 3 ]

Question (b)

(b)

Extinction of animal and plant species reduces biodiversity.

Explain why it is important to maintain biodiversity.

[ 7 ]

Question 3

[Maximum number: 10]

Question (a)

(a)

Many zoos around the world are involved in captive breeding programmes for endangered species.

Outline the role of zoos in the conservation of endangered species, other than captive breeding programmes.

[ 3 ]

Question (b)

(b)

Chester Zoo, in the United Kingdom, controls the European captive breeding programme for the eastern black rhinoceros, Diceros bicornis michaeli.

Fig. 10.1 shows an eastern black rhinoceros.

Fig. 10.1

Fig. 10.1

In the captive breeding programme for the eastern black rhinoceros, 15.8\% of females breed each year while in the wild 23.7 % of females breed each year.

Suggest reasons why fewer females breed in captivity than in the wild.

[ 4 ]

Question (c)

(c)

Sometimes assisted reproduction is used in captive breeding programmes for the eastern black rhinoceros.

Fig. 10.2 outlines the process of IVF that is used in these programmes.

Fig. 10.2

Fig. 10.2

Outline:
- the event A that occurs in the production of the embryos
- the two other possible outcomes, B and C, for the embryos that have been produced.

[ 3 ]
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