18.1. Classification
A subsection of Biology, 9700, through 18. Classification, biodiversity and conservation
Listing 10 of 21 questions
The Hawaiian archipelago is a group of volcanic islands in the Pacific ocean. shows the relative locations of five of these islands. O’ahu Lana’i Moloka’i Maui Hawai’i Table 4.1 shows the size and age of these five islands and the total number of Mecyclothorax ground beetle species and their species density, on each island. Data for the island of Maui is shown as two distinct regions, West and Haleakalã. This is because they formed at different times from two separate volcanoes. Table 4.1 island area / km2 age of island / million years total number of Mecyclothorax species species density / number of species per km2 Hawai’i 10 433 0.4 0.003 Lãna’i 1.3 0.008 Maui (West) 1.3 0.061 Maui (Haleakalã) 1.1 0.081 Moloka’i 1.9 – 1.8 0.064 O’ahu 3.7 – 2.6 shows a ground beetle of the genus Mecyclothorax. All the beetle species of this genus on the Hawaiian archipelago form a monophyletic group, descended from one original colonising species that reached Maui from Australia. Complete Table 4.1 by calculating the density of Mecyclothorax beetle species on the island of O’ahu. Use Table 4.1 to explain why the island of Hawai’i has the lowest density of Mecyclothorax beetle species. Use and Table 4.1 to suggest why O’ahu has a lower number of Mecyclothorax beetle species than Moloka’i. The rate of speciation of Mecyclothorax beetles on the slopes of the volcano Haleakalã, on Maui, is the highest recorded for any genus or location on earth. The volcano last erupted 400 years ago. This produced lava flows which cut through ancient forest and vegetation, dividing it into many separate microhabitats. Explain how the large number of Mecyclothorax beetle species on Haleakalã developed.
9700_w18_qp_43
THEORY
2018
Paper 4, Variant 3
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Most organisms are classified according to a taxonomic hierarchy. The hierarchy is shown in but the group names are not in the correct order. 1 – kingdom 2 – order 3 – genus 4 – family 5 – domain 6 – class 7 – species 8 – phylum Complete Table 8.1 by writing the numbers in the correct order. Table 8.1 Members of the Eukarya domain share similar features but will also have several differences. Complete Table 8.2 by stating the differences between the kingdoms Fungi and Plantae. Table 8.2 Fungi Plantae type of nutrition storage polysaccharide main component of cell wall Name the domain that contains organisms with a peptidoglycan cell wall. Viruses are not included in the three domain classification. Outline how viruses are classified.
9700_s20_qp_42
THEORY
2020
Paper 4, Variant 2
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All living organisms are divided into five kingdoms. The table below lists some features possessed by living organisms and some processes that they carry out. Place a tick or a cross in the table to indicate the presence or absence of the feature or process in any or all members of the kingdom. The first row has been done for you. feature or process kingdom Prokaryotae Protoctista Fungi Plantae Animalia 80s ribosomes ✗ ✓ ✓ ✓ ✓ cell walls contain chitin circular DNA endoplasmic reticulum most species unicellular autotrophic heterotrophic
9700_w09_qp_42
THEORY
2009
Paper 4, Variant 2
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shows two unicellular organisms, P and R. These organisms are members of different kingdoms. X 20 000 P R X 2 000 Calculate the actual sizes, in µm, of P and R, as shown by the lines on . Show your working. P µm R µm Examiner’s Use Identify the kingdom to which each organism belongs. Write your answers in the table below. Complete the table by listing five features which distinguish P from R. One has been completed for you. unicell P unicell R kingdom features cell wall present cell wall absent
9700_w07_qp_4
THEORY
2007
Paper 4, Variant 0
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Lichens are found growing on trees, walls, rocks and soil. shows a lichen of the genus Usnea. Usnea can tolerate only low concentrations of sulfur dioxide and does not grow in places where the air is polluted with sulfur dioxide. Usnea is composed of a mixture of two types of cell: • photosynthetic cells that are classified in the kingdom Protoctista • fungal cells that are classified in the kingdom Fungi. Outline the characteristic features of the kingdoms Protoctista and Fungi. Xanthoria is a lichen that can grow in places where there is a high concentration of sulfur dioxide in the air, for example in towns where homes, factories and vehicles burn fuels. shows a lichen of the genus Xanthoria. A student planned a method to measure the relative abundance of Usnea and Xanthoria on trees along a transect from the town centre at 0 km to unpolluted countryside at 4 km. Suggest why measuring the relative abundance of the two types of lichen gives information that is useful for conservation. … … … … … … Although a large biodiversity of lichens can be found in a range of habitats, most people ignore them. Outline why forms of life that are usually ignored, such as lichens, should be conserved. … … … …
9700_w24_qp_41
THEORY
2024
Paper 4, Variant 1
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Lichens are found growing on trees, walls, rocks and soil. shows a lichen of the genus Usnea. Usnea can tolerate only low concentrations of sulfur dioxide and does not grow in places where the air is polluted with sulfur dioxide. Usnea is composed of a mixture of two types of cell: • photosynthetic cells that are classified in the kingdom Protoctista • fungal cells that are classified in the kingdom Fungi. Outline the characteristic features of the kingdoms Protoctista and Fungi. Xanthoria is a lichen that can grow in places where there is a high concentration of sulfur dioxide in the air, for example in towns where homes, factories and vehicles burn fuels. shows a lichen of the genus Xanthoria. A student planned a method to measure the relative abundance of Usnea and Xanthoria on trees along a transect from the town centre at 0 km to unpolluted countryside at 4 km. Suggest why measuring the relative abundance of the two types of lichen gives information that is useful for conservation. … … … … … … Although a large biodiversity of lichens can be found in a range of habitats, most people ignore them. Outline why forms of life that are usually ignored, such as lichens, should be conserved. … … … …
9700_w24_qp_43
THEORY
2024
Paper 4, Variant 3
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Questions Discovered
21