Biodiversity and conservationIB Environmental Systems and Societies HL: Topic test

1. 1
   Before the Industrial Revolution almost all peppered moths (Biston betularia) in England were pale and speckled, which made them hard for birds to see on lichen-covered tree bark. The first dark (melanic) moth was recorded near Manchester in 1848. By 1895 about 98% of the moths near Manchester were dark, because soot from factories killed the lichens and blackened the tree trunks. After clean air laws were introduced in the 1950s, dark moths became less common again.

   (a)

   Which feature is necessary for natural selection to occur in a population?

   [1 mark]

   • AAll individuals are identical
   • BIndividuals change colour on purpose when the environment changes
   • COrganisms produce only as many offspring as will survive
   • DIndividuals vary in a heritable characteristic, such as colour

   (b)

   Why did dark moths become more common near Manchester?

   [1 mark]

   • ASoot caused a mutation in every moth
   • BDark moths were better camouflaged on blackened trunks, so more survived and reproduced
   • CBirds preferred to eat dark moths
   • DDark moths migrated from the countryside

   (c)

   Explain why pale moths became more common again after clean air laws were introduced.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   The Arabian oryx (Oryx leucoryx) was hunted until the last wild animal was shot in Oman in 1972, and the species was classed by the IUCN as Extinct in the Wild. Animals bred in zoos and reserves in the USA and the Middle East were returned to Oman from 1982, and protected areas were set up with the help of local people. In 2011 the IUCN improved its status to Vulnerable.

   (a)

   What is the IUCN Red List?

   [1 mark]

   • AA global assessment of the conservation status of species
   • BA list of products that cannot be traded between countries
   • CA treaty that gives every species legal protection
   • DA list of the species that have been successfully reintroduced

   (b)

   Which of the following is an ex situ conservation strategy used for the oryx?

   [1 mark]

   • ASetting up protected areas where oryx live in the wild
   • BBanning hunting of the oryx
   • CBreeding oryx in zoos and captive reserves
   • DProtecting the grazing land of the oryx

   (c)

   Explain how assigning a global conservation status to a species can help conservation.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   The Leuser Ecosystem in northern Sumatra, Indonesia, is one of the last places on Earth where orangutans, tigers, rhinoceroses and elephants all live in the same forest. It also provides water and fertile soil for millions of people living nearby. Large areas of lowland forest have been cleared for oil palm plantations and logging roads, and local communities are divided between those who want jobs and income from plantations and those who depend on the forest for food, fuel and medicines.

   (a)

   Outline why the Leuser Ecosystem could be identified as a key area for biodiversity conservation.

   [3 marks]

   (b)

   Evaluate why environmental justice should be considered when planning the conservation of the Leuser Ecosystem.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Geologists have proposed that Earth has entered a new epoch, the Anthropocene, beginning in the middle of the twentieth century. Evidence that will be found in rocks includes radioactive fallout from nuclear tests, plastics, concrete and large deposits of chicken bones. Earth is about 4.5 billion years old, and the fossil record shows five mass extinctions, the most recent about 66 million years ago. Current extinction rates are estimated to be many times higher than the natural background rate. Scientists also report that where fishing removes the largest fish, many populations now mature at smaller sizes.

   (a)

   Explain how Earth history, mass extinctions and human activity have shaped biodiversity.

   [6 marks]

   (b)

   Discuss how human activities have changed the selective forces acting on species, using named examples.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   The Knepp Estate in West Sussex, England, is about 1 400 hectares of former intensive farmland that has been rewilded since 2001. Free-roaming longhorn cattle, Exmoor ponies and Tamworth pigs shape the vegetation, and few other management actions are used. Scrub and wetland have developed, and species such as white storks, turtle doves and purple emperor butterflies have returned or increased.

   (a)

   What is the main aim of rewilding?

   [1 mark]

   • ATo return land to intensive farming
   • BTo protect one species in a zoo
   • CTo regenerate natural processes with minimal ongoing human management
   • DTo build tourist facilities

   (b)

   Which is an example of a positive feedback loop that rewilding can trigger?

   [1 mark]

   • AMore varied vegetation supports more insects and birds, which spread seeds and increase habitat diversity further
   • BIncreased grazing removes all vegetation so the system returns to its starting state
   • CFewer plants cause fewer animals, which causes fewer plants
   • DWildlife numbers are held constant by human control

   (c)

   Outline two limitations of rewilding projects.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   A government plans a nature reserve for a rare forest bird that needs large areas of undisturbed forest. Two designs are proposed. Design 1 is a single large circular reserve of 100 square kilometres. Design 2 is four separate square reserves of 25 square kilometres each, with farmland between them and no links. The land around both designs is farmed.

   (a)

   Why is Design 1 likely to protect the bird better than Design 2?

   [1 mark]

   • AA larger number of small reserves always protects more species
   • BIt is a large, compact area, so it can support a larger population and has less edge in proportion to its area
   • CCircular reserves have more edge, which gives the bird more food
   • DIt would be cheaper to buy farmland around a larger reserve

   (b)

   Which of the following is an in situ conservation strategy?

   [1 mark]

   • AStoring seeds in a seed bank
   • BBreeding birds in a zoo
   • CKeeping tissue samples frozen
   • DProtecting the forest where the bird lives in a nature reserve

   (c)

   Suggest two ways in which the design or management of Design 2 could be improved to protect the bird.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   A survey of birds in two coffee plantations in Costa Rica recorded 100 individuals of 5 species in each. Site A was grown in the shade of native trees and Site B was grown in full sun. The counts per species in Site A were 20, 20, 20, 20 and 20. The counts per species in Site B were 60, 20, 10, 6 and 4. Simpson's reciprocal index is D = N(N − 1) / Σn(n − 1), where N is the total number of individuals and n is the number of individuals of each species. For Site A, D = 5.2.

   (a)

   Calculate Simpson's reciprocal index for Site B. Show your working and give your answer to two significant figures.

   [3 marks]

   (b)

   Using the indices, compare the diversity of the two sites and evaluate the usefulness of the index for managing the plantations.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   Since 1996 Namibia has allowed rural communities to form conservancies that manage wildlife on communal land and earn income from tourism. Populations of elephants, lions and other wildlife have risen in many conservancies. However, there are conflicts when wild animals damage crops or kill livestock, and tourism income fell sharply when international travel stopped in 2020.

   (a)

   Explain the arguments for the conservation of species and habitats, using the justifications that can be made for it.

   [6 marks]

   (b)

   Evaluate ecotourism as a way of conserving biodiversity.

   [6 marks]

   Total for question 8: 12 marks

End of questions