18. Classification, biodiversity and conservation
A section of Biology, 9700
Listing 10 of 184 questions
Explain what is meant by the term biodiversity. Simpson’s Index of Diversity (D) is a method of assessing biodiversity. The formula for Simpson’s Index of Diversity is: D N n 2 = - J L K K J L KK N P OO N P O O / n = number of individuals of each species present in the sample N = total number of all individuals of all species In an investigation of biodiversity in a pond, samples of pond animals were removed using sampling nets. The species of each animal was identified and the number of individuals of each species was recorded. Table 8.1 shows the results of the investigation. Calculate Simpson’s Index of Diversity by completing Table 8.1 in the spaces provided. Record your values to three decimal places. Write the value for Simpson’s Index of Diversity on the dotted line. Record your value to three decimal places. Table 8.1 species number N n N n 2 J L KK N P OO Rana temporaria 0.042 0.002 Leucorrhinia dubia 0.148 0.022 Hydrometra stagnorum 0.212 0.045 Lymnaea stagnalis 0.186 0.035 Gammarus pulex total Simpson’s Index of Diversity (D) = Explain what this value for Simpson’s Index of Diversity shows about the diversity of the pond.
9700_m19_qp_42
THEORY
2019
Paper 4, Variant 2
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The sea otter, Enhydra lutris, is a marine mammal that lives on the coasts of the North Pacific ocean. shows a sea otter. Table 6.1 shows part of the classification of the sea otter. Table 6.1 taxonomic group name phylum Chordata Mammalia order Carnivora Mustelidae genus Enhydra species lutris Complete Table 6.1 by adding the correct taxonomic groups in the two spaces provided. There were estimated to be about 300 000 sea otters in the year 1700. • Extensive hunting for their fur resulted in the numbers of sea otters falling to about 1000 by the year 1911, when most hunting was banned. • The population size then increased to about 125 000 by the year 2012. All of the sea otters alive today are descended from the 1000 individuals alive in the year 1911. Outline the genetic consequences to a species, such as the sea otter, of having a large population that is descended from a very small number of individuals. Seaweeds, such as kelp, are large algae that can grow to be over 30 metres in length. In the ocean along the coasts of California, USA, there are very dense areas of kelp called kelp forests. Kelp forests are very productive and diverse ecosystems. shows a kelp forest. The sea otter is a keystone species in kelp forests along the coasts of California. This means that sea otters have a larger than expected effect on other organisms in these kelp forests. The loss of the sea otter would cause major changes to the kelp forest ecosystem and a reduction in biodiversity. Sea otters may spend up to five minutes under water while searching for food. During this time, respiration in anaerobic conditions takes place. When a sea otter first returns to the surface of the ocean, its breathing is faster and deeper than normal. Explain why its breathing is faster and deeper than normal. The striated muscle of the sea otter is composed of fibres called myofibrils. Myofibrils are made of units called sarcomeres. Describe the proteins that are involved in the contraction of a sarcomere.
9700_m20_qp_42
THEORY
2020
Paper 4, Variant 2
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The passage in is about biodiversity. Complete the passage by using the most appropriate scientific terms. Biodiversity within an area can be assessed at different levels, including the species diversity, genetic diversity and ecological diversity. Species diversity can be assessed by determining the number of different species and the relative of different species in a given area. From this information, species diversity can be estimated using index of diversity. Organisms of the same species can show much genetic diversity even though they share the same . This is because they can have different combinations of . The greater the genetic diversity, the greater the ability of a species to to a changing environment. Ecological diversity is a measure of the number and range of different ecosystems and within a given area. The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is updated regularly. Table 10.1 shows the numbers of endangered animal species counted every three years between 2007 and 2019. Table 10.1 year number of endangered species 7 851 9 618 11 212 12 630 14 234 Calculate the rate of increase in the number of endangered species between 2007 and 2019. Show your working. Give your answer to the nearest whole number. rate of increase = per year More species of fish were listed as endangered in 2019 than species of mammals. Suggest reasons why more fish species than mammal species are endangered.
9700_m23_qp_42
THEORY
2023
Paper 4, Variant 2
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The African elephant, Loxodonta africana, is a large herbivorous mammal which eats tree leaves. It has the longest gestation period of any land mammal and normally produces one offspring at a time. Its habitat is mainly savannah. Suggest how human activities have caused the African elephant to become endangered. The meerkat, Suricata suricatta, also lives in the savannah of southern Africa. It is a carnivorous mammal and feeds on insects, worms, snails and other invertebrates. It grows up to 30 cm in length and lives in large family groups in burrows. shows a meerkat. With reference to the information given, suggest why the meerkat is less likely than the elephant to become endangered.
9700_s09_qp_4
THEORY
2009
Paper 4, Variant 0
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Two species of animal are found in the same area of forest and grassland. In the spring and summer they eat the same plant food. However, in the autumn and winter one eats nuts in the forest and the other eats roots on the grassland. Both species are preyed upon by the same predator. Numbers of root-eating animals are reduced most by this, but they recover faster since they reproduce faster. What can be concluded about these two species of animals?
9700_s10_qp_11
MCQ
2010
Paper 1, Variant 1
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