18. Classification, biodiversity and conservation
A section of Biology, 9700
Listing 10 of 184 questions
The Visayan warty pig, Sus cebifrons, is found on two islands in the Philippines. shows a female Visayan warty pig with her young. 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 Visayan warty pig is categorised as critically endangered on the IUCN Red List, which means that it is nearly extinct in the wild. There are now only approximately 200 Visayan warty pigs in the Philippines. Visayan warty pigs live in areas of dense forest that may be close to human habitation. Suggest two reasons why the Visayan warty pig is critically endangered. Describe the role of zoos in the protection of the Visayan warty pig. Sometimes the Visayan warty pigs will breed with domestic pigs, Sus domesticus. Suggest the consequences of this interspecific breeding. Table 1.1 shows part of the classification of the Visayan warty pig. Complete Table 1.1. Table 1.1 taxonomic group name domain kingdom animalia phylum chordata mammalia order artiodactyla family suidae
9700_w18_qp_42
THEORY
2018
Paper 4, Variant 2
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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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A large number of alpine plant species grow in the mountains of New Zealand’s South Island. Alpine plants are defined as plants that live above the treeline, which is the height above which trees cannot grow. The current treeline for most of South Island is 1200 m. The alpine areas nearest to South Island are 1500–2000 km away across the sea. Many of South Island’s alpine species live nowhere else in the world. Explain how a large number of alpine plant species developed on South Island. shows two aspects of the history of South Island over the last 3.9 million years. • The dashed line shows how the mean height of mountains in the Clyde region of South Island increased over time. The mountains in this range have a mean height of 2400 m at the present time. • The solid line models the height of the treeline over time based on geological climate data. The treeline was higher when the climate was warmer, and the treeline was lower when the climate was colder, during ice ages. 3.0 2.0 time before present / million years present time height / m 1.0 3.9 With reference to , identify with reasons the time period when South Island’s alpine plant species developed. Suggest how DNA sequence data could be used to confirm the time period you identified in .
9700_w22_qp_41
THEORY
2022
Paper 4, Variant 1
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A large number of alpine plant species grow in the mountains of New Zealand’s South Island. Alpine plants are defined as plants that live above the treeline, which is the height above which trees cannot grow. The current treeline for most of South Island is 1200 m. The alpine areas nearest to South Island are 1500–2000 km away across the sea. Many of South Island’s alpine species live nowhere else in the world. Explain how a large number of alpine plant species developed on South Island. shows two aspects of the history of South Island over the last 3.9 million years. • The dashed line shows how the mean height of mountains in the Clyde region of South Island increased over time. The mountains in this range have a mean height of 2400 m at the present time. • The solid line models the height of the treeline over time based on geological climate data. The treeline was higher when the climate was warmer, and the treeline was lower when the climate was colder, during ice ages. 3.0 2.0 time before present / million years present time height / m 1.0 3.9 With reference to , identify with reasons the time period when South Island’s alpine plant species developed. Suggest how DNA sequence data could be used to confirm the time period you identified in .
9700_w22_qp_43
THEORY
2022
Paper 4, Variant 3
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Biodiversity can be assessed at three different levels. One of these is the genetic variation within each species. Outline two other levels at which biodiversity can be measured. To calculate the genetic variation that exists within a species, scientists: • obtain DNA sequences from many individuals of one species • count the number of nucleotides that differ when the sequences of two individuals are compared • repeat this with different pairs of individuals. This allows scientists to calculate the mean number of differences at every nucleotide position along the sequence (mean number of nucleotide differences per site). Explain why scientists use databases and computers to calculate the mean number of nucleotide differences per site. Table 2.1 shows the mean number of nucleotide differences per site of some species. Table 2.1 species mean number of nucleotide differences per site Drosophila melanogaster, fruit fly 0.0087 Anopheles gambiae, mosquito vector of malaria 0.0301 Plasmodium falciparum, malarial pathogen 0.0015 Zea mays, wild maize 0.0139 State the genus name of the species that shows the most genetic variation. State how many kingdoms of organisms are represented in Table 2.1. Genetic variation is considered important in the conservation of species. Low genetic variation is assumed to decrease the chance of the long-term survival of a species. Give reasons why low genetic variation may decrease the long-term survival of a species. shows how the International Union for the Conservation of Nature (IUCN) categorises species according to their conservation status. Common species with the lowest conservation status (least risk of extinction) are categorised as Least Concern (LC). conservation status Extinct (Eincreasing risk of extinction Extinct in the Wild (EW) Critically Endangered (CR) Endangered (EN) Vulnerable (VU) Near Threatened (NT) Least Concern (LC) Question 2states that ‘low genetic variation is assumed to decrease the chance of the long-term survival of a species’. Predict the relationship between genetic variation and conservation status if this assumption is true. shows the mean number of nucleotide differences per site of some species and sub-species of mammal and their conservation status. 0.0 0.1 0.2 mean number of nucleotide differences per site ×10–2 lion wolf giant panda brown rat chimpanzee gorilla common minke whale LC Key VU EN CR Assess whether the data in provide support for the prediction you made in 2.
9700_w23_qp_41
THEORY
2023
Paper 4, Variant 1
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The passage outlines one method of estimating the size of an animal population. Complete the passage by using the most appropriate scientific terms. The size of a population of animals can be estimated using the mark-release-recapture method. A sample of animals is captured using a humane trap and is counted. The animals are marked using a method that does not harm them. This can be done using a small tag or . The marked animals are released into the area where they were captured. Time is allowed for the marked animals to mix into the population. This period of time must be short so that emigration, immigration, migration or do not occur. A second sample of animals is then captured and the number of marked and unmarked animals is counted. The population size can be estimated using the Index. For reliability, the method should be . Himalayan balsam, Impatiens glandulifera, is an annual plant native to Pakistan, India and Nepal. It was first introduced into the United Kingdom (UK) in 1839 because of its attractive flowers. Individual plants can produce thousands of mature seeds. These can be dispersed for long distances when the capsules that contain the seeds burst. shows Himalayan balsam growing in a woodland. Himalayan balsam has now become established in the UK. It is listed as an invasive alien species and attempts are being made to eradicate the plant. Not all alien plant species are considered to be invasive. Suggest why Himalayan balsam has been listed as an invasive alien species in the UK.
9700_w23_qp_42
THEORY
2023
Paper 4, Variant 2
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Biodiversity can be assessed at three different levels. One of these is the genetic variation within each species. Outline two other levels at which biodiversity can be measured. To calculate the genetic variation that exists within a species, scientists: • obtain DNA sequences from many individuals of one species • count the number of nucleotides that differ when the sequences of two individuals are compared • repeat this with different pairs of individuals. This allows scientists to calculate the mean number of differences at every nucleotide position along the sequence (mean number of nucleotide differences per site). Explain why scientists use databases and computers to calculate the mean number of nucleotide differences per site. Table 2.1 shows the mean number of nucleotide differences per site of some species. Table 2.1 species mean number of nucleotide differences per site Drosophila melanogaster, fruit fly 0.0087 Anopheles gambiae, mosquito vector of malaria 0.0301 Plasmodium falciparum, malarial pathogen 0.0015 Zea mays, wild maize 0.0139 State the genus name of the species that shows the most genetic variation. State how many kingdoms of organisms are represented in Table 2.1. Genetic variation is considered important in the conservation of species. Low genetic variation is assumed to decrease the chance of the long-term survival of a species. Give reasons why low genetic variation may decrease the long-term survival of a species. shows how the International Union for the Conservation of Nature (IUCN) categorises species according to their conservation status. Common species with the lowest conservation status (least risk of extinction) are categorised as Least Concern (LC). conservation status Extinct (Eincreasing risk of extinction Extinct in the Wild (EW) Critically Endangered (CR) Endangered (EN) Vulnerable (VU) Near Threatened (NT) Least Concern (LC) Question 2states that ‘low genetic variation is assumed to decrease the chance of the long-term survival of a species’. Predict the relationship between genetic variation and conservation status if this assumption is true. shows the mean number of nucleotide differences per site of some species and sub-species of mammal and their conservation status. 0.0 0.1 0.2 mean number of nucleotide differences per site ×10–2 lion wolf giant panda brown rat chimpanzee gorilla common minke whale LC Key VU EN CR Assess whether the data in provide support for the prediction you made in 2.
9700_w23_qp_43
THEORY
2023
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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Questions Discovered
184