Consider supporting us on Patreon. Help us keep revisedeck free.
18. Classification, biodiversity and conservation
A section of Biology, 9700
Listing 10 of 184 questions
shows the relationship between annual deforestation rates and annual human population growth for six countries. percentage annual deforestation rate percentage annual human population growth V B N P I Z B – Burundi P – Philippines N – Nigeria I – Indonesia Z – Zimbabwe V – Vietnam Describe the relationship shown in . Over half of the species of plants and animals comprising the biodiversity of the Earth are thought to exist in tropical rainforests. Explain the meaning of the term biodiversity. Explain the economic reasons for maintaining biodiversity.
9700_s08_qp_4
THEORY
2008
Paper 4, Variant 0
View
The hedgehog, Erinaceus europaeus, is a small carnivorous mammal native to Northern Europe. shows a hedgehog. Hedgehogs were introduced onto a small group of islands off the west coast of Scotland in 1974. The hedgehog population has increased so that there are now over 5 000 breeding pairs. These hedgehogs have no natural predators on these islands and their diet consists mainly of bird’s eggs. shows the hedgehog population density in the year 2000. north island south island 10 km Key high / medium density low density absent Table 8.1 shows the changes in the populations of the species of birds from 1983 to 2000. Table 8.1 breeding pairs in breeding pairs in % change in population north island oystercatcher +21 lapwing +24 redshank +51 south island oystercatcher +55 lapwing –31 redshank –41 Using and Table 8.1, describe the relationship between the hedgehog population density and the changes in the populations of lapwings and redshanks. Suggest an explanation for the increase in the oystercatcher population on the south island, despite the increase in the hedgehog population. Explain why the population of hedgehogs on one of these islands may eventually become a different species from that on mainland Scotland.
9700_s11_qp_41
THEORY
2011
Paper 4, Variant 1
View
Sarawak is an area of south-east Asia that is largely covered by tropical rainforest. Logging has been allowed in large parts of the forest. A study was carried out to estimate the population size of different species of mammals living in the rainforest: • before logging • immediately after logging • two years after logging • four years after logging. Table 8.1 shows the results of the study for six species of mammal. Where numbers were too small to measure the population density, the species were recorded as “present”. Table 8.1 mean number of animals km−2 mammal before logging immediately after logging two years after logging four years after logging marbled cat present small-clawed otter present giant squirrel treeshrew small squirrel barking deer present Calculate the percentage rise in the small squirrel population from before logging to two years after logging. Show your working. answer % Suggest why populations, such as that of the small squirrel, do not increase in size indefinitely. Suggest why marbled cats and small-clawed otters became extinct in this area but the other mammals did not.
9700_s13_qp_41
THEORY
2013
Paper 4, Variant 1
View
Sarawak is an area of south-east Asia that is largely covered by tropical rainforest. Logging has been allowed in large parts of the forest. A study was carried out to estimate the population size of different species of mammals living in the rainforest: • before logging • immediately after logging • two years after logging • four years after logging. Table 8.1 shows the results of the study for six species of mammal. Where numbers were too small to measure the population density, the species were recorded as “present”. Table 8.1 mean number of animals km−2 mammal before logging immediately after logging two years after logging four years after logging marbled cat present small-clawed otter present giant squirrel treeshrew small squirrel barking deer present Calculate the percentage rise in the small squirrel population from before logging to two years after logging. Show your working. answer % Suggest why populations, such as that of the small squirrel, do not increase in size indefinitely. Suggest why marbled cats and small-clawed otters became extinct in this area but the other mammals did not.
9700_s13_qp_43
THEORY
2013
Paper 4, Variant 3
View
Questions Discovered
184