18. Classification, biodiversity and conservation
A section of Biology, 9700
Listing 10 of 184 questions
State the term for each of the following: all organisms of the same species living in a defined area at a particular time. the interaction of all living organisms with each other and their non-living environment in a self-contained location the process of converting nitrate ions in soil to nitrogen gas in the atmosphere. Mangroves are trees which grow on tropical coastlines in salt water. shows part of a food chain from a mangrove area. mangrove leaves crabs Pied Oystercatchers Name the trophic level of the Pied Oystercatchers. Explain why the energy taken in by the crabs is not all available to the Pied Oystercatchers. The crabs in also feed on mangrove leaves that have fallen to the ground. The leaves which are not eaten supply a source of nitrogen for the mangrove trees. Explain how nitrogen from compounds in the dead leaves is made available to the growing plants.
9700_w11_qp_23
THEORY
2011
Paper 2, Variant 3
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The Ethiopian wolf, Canis simensis, is a member of the Canidae family of carnivores. shows an Ethiopian wolf. Ethiopian wolves evolved from an ancestor similar to the grey wolf that crossed into Northern Africa from Europe about 100 000 years ago. They live in the alpine grasslands and heathlands at, or above, 3000 m altitude in Ethiopia. State the most likely type of speciation that led to the evolution of the Ethiopian wolf. A population of Ethiopian wolves is called a pack. Heterozygosity has been found to be low in all of the packs of Ethiopian wolves that have been studied. Suggest why the heterozygosity may be low in Ethiopian wolf packs. The Ethiopian wolf is classified as an endangered species by the International Union for the Conservation of Nature and Natural Resources (IUCN). It publishes an annual list of endangered species called the Red List. Complete Table 1.1 to summarise four of the main reasons, with further explanation, as to why the Ethiopian wolf has become an endangered species. Table 1.1 reason explanation an activity that accompanies human expansion and reduces the size of the wolf habitat rabies, a lethal viral disease of wolves a human activity to control wolves, considered to be pests the result of wolves breeding with domestic dogs According to the Red List, the number of endangered mammal species in 2007 was 349 and in 2008 was 448. Calculate the percentage increase in endangered mammal species between 2007 and 2008. Give your answer to the nearest whole number. Show your working. answer %
9700_w11_qp_41
THEORY
2011
Paper 4, Variant 1
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The Ethiopian wolf, Canis simensis, is a member of the Canidae family of carnivores. shows an Ethiopian wolf. Ethiopian wolves evolved from an ancestor similar to the grey wolf that crossed into Northern Africa from Europe about 100 000 years ago. They live in the alpine grasslands and heathlands at, or above, 3000 m altitude in Ethiopia. State the most likely type of speciation that led to the evolution of the Ethiopian wolf. A population of Ethiopian wolves is called a pack. Heterozygosity has been found to be low in all of the packs of Ethiopian wolves that have been studied. Suggest why the heterozygosity may be low in Ethiopian wolf packs. The Ethiopian wolf is classified as an endangered species by the International Union for the Conservation of Nature and Natural Resources (IUCN). It publishes an annual list of endangered species called the Red List. Complete Table 1.1 to summarise four of the main reasons, with further explanation, as to why the Ethiopian wolf has become an endangered species. Table 1.1 reason explanation an activity that accompanies human expansion and reduces the size of the wolf habitat rabies, a lethal viral disease of wolves a human activity to control wolves, considered to be pests the result of wolves breeding with domestic dogs According to the Red List, the number of endangered mammal species in 2007 was 349 and in 2008 was 448. Calculate the percentage increase in endangered mammal species between 2007 and 2008. Give your answer to the nearest whole number. Show your working. answer %
9700_w11_qp_42
THEORY
2011
Paper 4, Variant 2
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The Bengal Tiger, Panthera tigris tigris, is an endangered mammalian species of Southern Asia. It lives mostly in a forest habitat. shows a Bengal Tiger. Table 1.1 shows the relationship between available forest habitat and Bengal Tiger numbers between 1970 and 2010. Table 1.1 year forest habitat remaining compared to 1970 (%) Bengal Tiger numbers 37 000 27 000 12 000 3 600 1 400 Calculate the percentage decrease in the number of Bengal Tigers between 1970 and 2010. Give your answer to the nearest whole number. answer % Suggest methods to conserve the Bengal Tiger. The Bengal Tiger belongs to the kingdom Animalia. State two differences between members of the kingdom Animalia and the kingdom Plantae.
9700_w11_qp_43
THEORY
2011
Paper 4, Variant 3
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Corals are simple marine animals and usually exist in colonies of thousands of individuals. shows a coral colony. Corals absorb calcium carbonate from the sea to build their skeletons, which help to form large coral reefs. Coral reefs provide a home for about 25% of known fish species and have the highest biodiversity of any marine ecosystem. Corals, although they are animals, are sometimes mistaken for members of the plant kingdom. State two ways in which corals differ from plants. Outline what is meant by the term ecosystem. Coral reefs are at risk of damage due to human activities. All the coral reefs in three regions were classified as being at low, medium or high risk of damage. Table 7.1 shows the areas of coral reef at risk of damage in these three regions. Table 7.1 region area of coral reef at risk of damage / 1000 km2 percentage of coral reef at high risk of damage low medium high Caribbean Sea Indian Ocean Pacific Ocean Complete Table 7.1, giving your answers to the nearest whole number. Suggest how human activities could damage coral reefs.
9700_w12_qp_41
THEORY
2012
Paper 4, Variant 1
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Corals are simple marine animals and usually exist in colonies of thousands of individuals. shows a coral colony. Corals absorb calcium carbonate from the sea to build their skeletons, which help to form large coral reefs. Coral reefs provide a home for about 25% of known fish species and have the highest biodiversity of any marine ecosystem. Corals, although they are animals, are sometimes mistaken for members of the plant kingdom. State two ways in which corals differ from plants. Outline what is meant by the term ecosystem. Coral reefs are at risk of damage due to human activities. All the coral reefs in three regions were classified as being at low, medium or high risk of damage. Table 7.1 shows the areas of coral reef at risk of damage in these three regions. Table 7.1 region area of coral reef at risk of damage / 1000 km2 percentage of coral reef at high risk of damage low medium high Caribbean Sea Indian Ocean Pacific Ocean Complete Table 7.1, giving your answers to the nearest whole number. Suggest how human activities could damage coral reefs.
9700_w12_qp_42
THEORY
2012
Paper 4, Variant 2
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In some ecosystems, certain species fulfil important roles in maintaining biodiversity in communities. These species are often known as keystone species. The sea otter, Enhydra lutris, is found in waters of the northern and eastern coasts of the Pacific, where it occupies a niche as a predator. These coastal waters are rich in kelp communities. Kelp are very large seaweeds that form ‘underwater forests’. In the 19th century the sea otter was hunted for its fur, with the result that populations decreased. A consequence of this reduction in numbers was the disappearance of much of the kelp. Conservation measures in the 20th century restored the numbers of sea otters. shows the food web for this ecosystem. sharks sea otters large carnivorous fish starfish (sea stars) abalones large crabs small carnivorous fish and invertebrates scallops and sessile invertebrates microscopic floating animals detritus kelp (very large seaweeds) smaller seaweed phytoplankton small herbivorous invertebrates small herbivorous fish sea urchins Explain the meaning of the terms niche and community. niche community With reference to the food web in , suggest why sea otters are considered to be a keystone species. Suggest how the efficiency of energy transfer from kelp to sea urchins could be determined.
9700_w13_qp_21
THEORY
2013
Paper 2, Variant 1
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Read the following passage. The three-toed sloth, Bradypus variegatus, is a very slow-moving mammal found in Central and South America that spends most of its life living in trees. The thick, long grey fur of the sloth in has a green appearance. Individual hairs of the sloth have grooves in them where water can collect. Research has shown that the green colour is due to the presence of algae living on the sloth’s fur, the most common species being Trichophilus welckeri. Algae are eukaryotic, photosynthetic organisms. Many other species of non-photosynthetic eukaryotes, both unicellular and multicellular, have been found living on the sloth’s fur. These include different species of roundworms, insects and saprotrophic fungi. Explain the ecological terms population and community, using examples given in the passage. population community Suggest why the sloth and its fur can be described as a small ecosystem.
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THEORY
2013
Paper 2, Variant 2
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The tiger, Panthera tigris, is classified as an endangered species by the International Union for the Conservation of Nature and Natural Resources (IUCN). The IUCN publishes an annual list of endangered species called the Red List. shows the number of tigers in the wild between 1900 and 2010. 100 000 90 000 80 000 70 000 60 000 50 000 40 000 30 000 20 000 10 000 1900 1910 1920 1930 1940 1950 1960 year number of tigers in the wild 1970 1980 1990 2000 2010 Calculate the overall rate of decrease in number of tigers between 1900 and 2010. Give your answer to the nearest whole number. answer tigers per year Describe the reasons why a named species has become endangered.
9700_w13_qp_41
THEORY
2013
Paper 4, Variant 1
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Questions Discovered
184