CAIE A-Level Biology 18 Classification, Biodiversity & Conservation
Practise classifying organisms, quantifying biodiversity and evaluating conservation strategies from biological and field data.
- Syllabus
- 2028–2030
- Course
- Biology 9700
- Level
- A2
Covered syllabus points
18. Classification, Biodiversity and Conservation question 1
Question (a)
(a)
The Asian common toad, Duttaphrynus melanostictus, arrived accidentally in eastern Madagascar in 2010 on a ship.
Fig. 9.1 shows an Asian common toad.
Fig. 9.1
The Asian common toad is now regarded as an invasive alien species because:
- it breeds fast in the warm, wet conditions of eastern Madagascar
- it can travel up to 2.5 km per year
- its skin contains poison, which is highly toxic to humans and predators.
Suggest ways in which the Asian common toad may affect the ecosystem of eastern Madagascar.
[ 4 ]
Question (b)
(b)
Zoos work with local groups around the world to help conserve endangered species. One example of this is the use of assisted reproduction, such as IVF, with endangered mammals such as the eastern black rhino.
Outline the process of IVF.
[ 4 ]
18. Classification, Biodiversity and Conservation question 2
Bears are several species of mammal in the family Ursidae.
Climate change and loss of habitats due to human activity have reduced the size of some bear populations in recent years.
Question (a)
(a)
The International Union for Conservation of Nature (IUCN) has a role in the conservation of species, such as species of bear.
Outline the role of the IUCN in the conservation of species.
[ 3 ]
Question (b)
(b)
Grizzly bears, Ursus arctos horribilis, and polar bears, Ursus maritimus, are found in North America.
Fig. 8.1 shows a grizzly bear and a polar bear.
Grizzly bears have:
- a varied diet that includes grasses, roots, berries, nuts, rodents, insects and fish
- a habitat of woodland or grassland
- a maximum mass of 270 kg .
Polar bears have:
- a diet that consists of other animals, such as seals
- a habitat of land and sea ice
- a maximum mass of 450 kg .
Climate change has caused populations of grizzly bears to spread further north and populations of polar bears to spread further south. In some areas there is habitat overlap and, on rare occasions, breeding between grizzly bears and polar bears has occurred.
The offspring of grizzly bears and polar bears are known as pizzly bears.
Pizzly bears can breed together in the wild.
Fig. 8.2 shows a pizzly bear.
Fig. 8.2
With reference to three different species concepts, discuss whether grizzly bears and polar bears should be classified as separate species.
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Question (c)
(c)
Human activity has disturbed the habitat of many populations of spectacled bear, Tremarctos ornatus. The spectacled bear feeds on a variety of plant and animal species.
Scientists compared the diversity of the food eaten by two populations of spectacled bear by analysing their faeces. One population lived in an undisturbed habitat and the other population lived in a habitat that had been disturbed by road building.
The scientists analysed the faeces from 60 bears in each population. They identified the species present and the number of individuals of each species in the faeces.
The scientists calculated the diversity of species in the faeces of the two populations using Simpson's Index of Diversity.
The formula for Simpson's Index of Diversity is:
n= number of individuals of each species present in the sample
N= total number of all individuals of all species
Table 8.1 shows the results and some of the steps for calculating the D value for the disturbed population.
Table 8.1
Calculate Simpson's Index of Diversity by completing Table 8.1 in the spaces provided.
Write the value for Simpson's Index of Diversity on the dotted line.
[ 3 ]
Question (d)
(d)
The scientists calculated a D value of 0.833 for the undisturbed population.
Explain what is shown by the difference in the D values between the two populations of bear.
[ 1 ]
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