18. Classification, biodiversity and conservation
A section of Biology, 9700
Listing 10 of 184 questions
The American crocodile, Crocodylus acutus, was classified as an endangered species by the USA in 1975. It is found in estuarine regions of southern Florida. shows an American crocodile. The salinity of the water was thought to play a part in the distribution of the American crocodile. shows the number of American crocodile nest sites in areas with water of varying salinity in southern Florida. number of nest sites 0-5 6-10 11-15 16-20 water salinity / parts per thousand 21-25 26-30 31-35 Describe the results shown in . Much conservation work has been done in the Everglades National Park in Florida, which is a large wetland area. As a result the number of nest sites has increased from 8 in 1975 to 31 in 2000. This has led to a rise in the number of crocodiles. Calculate the percentage increase in nest sites between 1975 and 2000. Show your working. answer % Suggest two reasons why the population of crocodiles in the Everglades National Park has increased. 1. 2.
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THEORY
2010
Paper 4, Variant 3
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The polar bear, Ursus maritimus, lives in the Arctic regions of the USA, Canada, Norway and Russia. Polar bears move across the Arctic ice sheet to hunt prey such as seals. shows a polar bear. The area over which the Arctic ice sheet extends varies throughout the year. shows the variation in the extent of the Arctic ice sheet for the months of July to November for the years 1979 and 2009. July Aug Sept month Oct Nov extent of Arctic ice sheet / km2 × 106 Key Calculate the percentage reduction in the area over which the ice sheet extends between 1979 and 2009 for the month of September. Give your answer to the nearest whole number. Show your working. answer % In 2008 the government of the USA classified U. maritimus as an endangered species because it is under threat of extinction. Suggest what has caused U. maritimus to have become endangered. U. maritimus is a eukaryote. Beneficial bacteria, which are prokaryotic cells, live in the gut of U. maritimus. State three differences between the cells of U. maritimus and its gut bacteria. 1. 2. 3.
9700_s11_qp_41
THEORY
2011
Paper 4, Variant 1
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Lancaster Sound in the Canadian Arctic is a very productive marine environment and supports large populations of sea birds and marine mammals. Studies of the area have shown the importance of Arctic cod, Boreogadus saida, in the flow of energy to marine birds, such as guillemots and fulmars, and marine mammals, such as narwhals and belugas. Arctic cod forms the main, or only, source of food for many such animals. The flow of energy through the food web in Lancaster Sound is shown in . gull polar bear human guillemot narwhal Arctic cod copepods amphipods arrow worms walrus bivalve molluscs algae kelp phytoplankton detritus harp seal fulmar Note: detritus is dead and decaying matter ringed seal beluga Name the trophic levels occupied by the following organisms in the food web in : kelp arrow worms narwhals. The population of polar bears in the Lancaster Sound area is quite small in comparison to populations of animals that feed on Arctic cod. Using only the information shown in , explain why the population of polar bears is small. Populations of many fish species are under threat of extinction as a result of over-fishing. Explain the likely consequences of over-fishing of Arctic cod.
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THEORY
2012
Paper 2, Variant 1
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The moose, Alces alces, is a large member of the deer family. It lives in temperate forests in North America and northern Europe, where snow is present for large parts of the year. shows an adult male moose feeding in a lake. The moose feeds on a plant in the lake called watermilfoil, Myriophyllum aquaticum. The moose and the watermilfoil belong to the domain Eukarya, which includes the kingdoms Animalia and Plantae. Describe the main differences between the kingdom Animalia and the kingdom Plantae. 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 . 1880 1890 1900 1910 1920 1930 1940 1950 year 1960 1970 1980 1990 2000 2010 2020 –0.4 –0.3 –0.2 –0.1 0.0 +0.1 +0.2 +0.3 +0.4 +0.5 +0.6 +0.7 +0.8 +0.9 calculated temperature difference / °C mean for the twentieth century Calculate the rate of increase in temperature per decade between 1980 and 2020. Show your working. Write your answer to two decimal places. answer °C per decade Moose populations have decreased in North America since 1980. Suggest and explain reasons for the decrease in moose populations.
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THEORY
2023
Paper 4, Variant 3
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The IUCN Red List provides information about the conservation status of species throughout the world, including the American badger, Taxidea taxus, and the black-footed ferret, Mustela nigripes. shows an American badger and shows a black-footed ferret. shows the IUCN conservation status of the American badger and the black-footed ferret in 1987 and in 2013. American badger, T. taxus conservation status American badger, T. taxus black-footed ferret, M. nigripes black-footed ferret, M. nigripes critically endangered extinct in the wild endangered vulnerable near threatened least concern American badgers and black-footed ferrets are both predators. • American badgers feed on prairie dogs and a range of other animals. • Black-footed ferrets feed almost entirely on prairie dogs. • American badgers do not have any animal predators. • Black-footed ferrets are preyed upon by American badgers and several other predators. Suggest reasons why black-footed ferrets are an endangered species but American badgers are not. In 1987, the world population of black-footed ferrets consisted of only 18 animals living in captivity. A number of different agencies worked together to prevent the extinction of this species. Their goal was to produce young black-footed ferrets to be released into the wild. The survival and breeding of the animals in the wild would then be monitored and supported. The collaborating agencies included: • local government • universities • zoos • native tribes that owned undeveloped reservation land. Outline how these different agencies could contribute to successful conservation of the black-footed ferret. Black-footed ferrets were released at three different locations in the wild at different times. Each population was established from captive-bred animals. shows the population sizes of black-footed ferrets at the three release locations. year population size / number of individuals South Dakota Wyoming Arizona Describe the patterns of population growth at the three locations where black-footed ferrets were released. Table 2.1 shows information about the gene pool of the populations of black-footed ferrets and the leg sizes of the black-footed ferrets at each release location in 2004. All three populations were started by animals from the same captive population. In this original captive population, 100% of the genes surveyed showed polymorphism, that is, they had more than one allele. The mean number of alleles per gene locus was two. The population at the South Dakota location in 2004 maintained the same level of genetic variation and leg size data as the original captive population, but the populations in Wyoming and Arizona showed changes. Table 2.1 population location gene pool data leg size data percentage of genes that are polymorphic mean number of alleles per gene locus mean length of lower back leg bone / mm mean length of lower front leg bone / mm South Dakota 2.00 69.4 59.0 Wyoming 1.43 68.0 56.7 Arizona 2.14 69.4 59.0 Use Table 2.1 to describe how the gene pools and leg sizes of the Wyoming and Arizona black-footed ferret populations have changed, compared to the original captive population. With reference to , suggest reasons for the changes you have described in . In 2008 some black-footed ferrets were born in captivity as a result of IVF using frozen sperm that had been stored for several years. Explain the benefits of using frozen sperm in captive breeding programmes.
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THEORY
2016
Paper 4, Variant 2
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Palm oil is an edible vegetable oil that comes from the fruit of oil palm trees. • Palm oil is cheap. • It is the world’s most widely used vegetable oil. • The yield of oil per hectare from oil palm trees is thirty times more than that of oil from maize. • Around 85% of the world’s palm oil is now produced in Indonesia. Table 8.1 shows the change in forest cover on the three main Indonesian islands between 2000 and 2010. Table 8.1 island Sumatra Borneo Java area of island / million hectares forest cover in 2000 / million hectares forest cover in 2010 / million hectares loss of forest cover between 2000 and 2010 / million hectares percentage loss of forest cover between 2000 and 2010 Complete Table 8.1 to show the loss of forest cover and the percentage loss of forest cover for Borneo between 2000 and 2010. The Sumatran forest is the natural habitat for the Sumatran orangutan, Pongo abelii. shows a Sumatran orangutan. The Sumatran orangutan is classified as critically endangered on the IUCN Red List of Threatened Species. Loss of forest cover can separate family groups from other groups. Suggest the genetic consequences of the separation of family groups. Suggest ways in which the Sumatran orangutan can be protected in its natural environment. Describe the role of zoos in the protection of endangered species such as the Sumatran orangutan.
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THEORY
2017
Paper 4, Variant 2
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The western lowland gorilla, Gorilla gorilla, has become an endangered species although it has no known enemies, except humans. Gorillas are herbivorous, feeding on fruit, shoots, tree bark and leaves. shows a western lowland gorilla. Suggest three reasons why the western lowland gorilla has become an endangered species. 1. 2. 3. Explain how captive breeding programmes in zoos may help in the protection of endangered species, such as the western lowland gorilla. Examiner’s Use State two disadvantages of captive breeding programmes. 1. 2.
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THEORY
2007
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The Sumatran orangutan, Pongo abelii, is found only on the island of Sumatra, Indonesia. shows a Sumatran orangutan. The International Union for Conservation of Nature (IUCN) is the world’s largest global environmental organisation. The IUCN Red List of Threatened Species™ evaluates the conservation status of plant and animal species. The Sumatran orangutan is categorised as critically endangered on the IUCN Red List. The Sumatran orangutan spends most of its time in trees and is very sensitive to habitat destruction. Table 1.1 shows the area of natural forest of Sumatra and the numbers of orangutans in 1985 and 2016. Table 1.1 area of natural forest / million hectares 25.3 12.4 number of orangutans 25 000 With reference to Table 1.1, state the relationship between area of natural forest and number of orangutans. Calculate the mean annual decrease in orangutan numbers between 1985 and 2016. Show your working. Give your answer to the nearest whole number. mean annual decrease = Use your answer from to estimate the number of years after 2016 that it will take for the Sumatran orangutan to become extinct in the wild, if conservation work is unsuccessful. years Suggest two reasons for the decrease in numbers of Sumatran orangutans, other than habitat loss. Outline the role zoos can take in the protection of the Sumatran orangutan.
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THEORY
2018
Paper 4, Variant 1
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The Sumatran tiger lives on the island of Sumatra, Indonesia. shows a Sumatran tiger. The International Union for Conservation of Nature (IUCN) is the world’s largest global environmental organisation. The IUCN Red List of Threatened Species™ evaluates the conservation status of plant and animal species. The Sumatran tiger is categorised as critically endangered on the IUCN Red List. There are approximately 400 Sumatran tigers left in the wild. Suggest reasons why the Sumatran tiger has become critically endangered. Some zoos in Europe have captive breeding programmes for the Sumatran tiger, which breeds well in captivity. Once cubs have reached maturity they may be moved to other zoos. For example, as part of a coordinated breeding programme carried out in 2013, one tiger born in Chester Zoo in England was moved to France and another tiger born in the same zoo was moved to Germany. This type of coordinated breeding programme is essential for the survival of the Sumatran tiger. Explain why it is important to the gene pool of Sumatran tigers to move tigers from one zoo to another. Some animals do not breed well in captivity. List the methods of assisted reproduction that may be used with animals that do not breed well in captivity.
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THEORY
2018
Paper 4, Variant 2
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Questions Discovered
184