20.4. Conservation
A subsection of Biology, 0610, through 20. Human influences on ecosystems
Listing 10 of 99 questions
is a photograph of a lionfish (Pterois volitans). State the genus of the lionfish. Lionfish are classified as fish. Table 7.1 shows features of organisms. Place ticks (✓) in the boxes to show the correct features of birds, fish and insects. Table 7.1 features birds fish insects compound eyes feathers internal skeleton Lionfish are an example of a foreign species that has been accidentally introduced to many marine habitats. Describe the harmful consequences of introducing a foreign species to a habitat. Removing introduced species from habitats is one method of conserving endangered species. Describe other methods of conserving endangered species.
0610_w23_qp_33
THEORY
2023
Paper 3, Variant 3
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For Examiner's Use shows a goliath beetle, Goliathus giganteus. State two features, visible in , that show that Goliathus giganteus is an arthropod. For Examiner's Use Use the key to identify each species. Write the letter of each species, B to H, in the correct box in the key. One, A, has been done for you. Key 1 Wings present go to 2 Wings absent go to 7 2 Back legs adapted for jumping Schistocerca gregaria A Back legs not adapted for jumping go to 3 3 Two pairs of wings go to 4 One pair of wings Drosophila melanogaster 4 Wings with hairs go to 5 Wings with no hairs go to 6 5 Hairs on back wings longer than width of back wing Ephestia cautella Hairs on back wings shorter than width of back wing Batrachedra amydraula 6 Thorax with spots Rhynchophorus ferrugineus Thorax with no spots Oryctes agamemnon 7 Three pairs of legs Microcerotermes diversus Four pairs of legs Oligonychus afrasiaticus For Examiner's Use Pesticides can be sprayed onto date palms to kill pests. This can damage the environment. Outline the damage to the environment that may be done by spraying pesticides. An alternative to using pesticides is biological control. The Senegalese grasshopper is a serious pest in West Africa. A fungal parasite of grasshoppers is used as a means of biological control. Spores of the fungus are sprayed onto populations of grasshoppers. An investigation was carried out to compare this biological control with a pesticide. Three fields were treated as follows: • sprayed with fungal spores • sprayed with pesticide • not sprayed Explain why one field was not sprayed. For Examiner's Use The population density of grasshoppers was recorded for 22 days after spraying. The results are shown in . mean population of Senegalese grasshoppers / number per m2 time / days time of spraying field not sprayed field sprayed with pesticide field sprayed with fungal spores Describe the effects of the two sprays on the populations of grasshoppers. You will gain credit if you use data from to support your answer. pesticide fungal spores For Examiner's Use Explain the differences between the effects of the pesticide and the fungal spores on the grasshoppers, as shown in .
0610_s12_qp_33
THEORY
2012
Paper 3, Variant 3
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The giant quiver tree, Aloe pillansii, shown in , is an endangered species. These long-lived trees grow in harsh environments. Some populations of A. pillansii are found within the Richtersveld National Park, but one population is found just outside on a mountain called Cornell’s Kop in southern Africa. State the genus of the giant quiver tree. Explain why the A. pillansii trees on Cornell’s Kop represent a population. Suggest three reasons why the giant quiver tree is an endangered species. It was estimated in 2005 that the total number of giant quiver trees in the wild was less than 3000, which is considered to be very low compared with other tree species. Explain the risks to a plant species of having very small numbers. The population of A. pillansii trees on Cornell’s Kop was surveyed and photographed at four sites, A to D, from 1937 onwards. Researchers took photographs at all four sites in 2004 and compared them with the original photographs. The results are shown in Table 5.1. Table 5.1 site date of the original photograph number of living trees in the original photograph number of living trees in number of dead tree stumps average annual mortality rate / percentage of deaths per year A 1.0 B 0.9 C 2.1 D 5.6 Calculate the percentage decrease in the number of living trees at site B from 1953 to 2004. Show your working and give your answer to the nearest whole number. % Describe what the analysis of the photographs shows about the population of A. pillansii on Cornell’s Kop.
0610_s17_qp_41
THEORY
2017
Paper 4, Variant 1
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is a photograph of a yellow-shouldered Amazon, Amazona barbadensis, a species of parrot found along the Venezuelan coast of the Caribbean. State the vertebrate group that includes A. barbadensis and give two features that are used to classify animals into this group. vertebrate group feature 1 feature 2 This species is subdivided into several populations on the mainland and on the islands of Margarita and Bonaire. Scientists believe that yellow-shouldered Amazons rarely travel between these places. Explain what biologists mean when they refer to populations of animals, such as A. barbadensis. The number of yellow-shouldered Amazons on Margarita Island had decreased to 700 parrots by 1989. The population then increased to 1600 parrots by 2009. Part of this increase was due to the release of captive-bred parrots on the island. This is one of the few successful release programmes of parrots. A similar release programme in Arizona in the 1980s of a different species of parrot was not successful. Suggest why release programmes for captive-bred parrots were not successful. Some captive breeding programmes involve very small numbers of animals. Outline the disadvantages of such programmes. Many biologists think that it is better to conserve ecosystems rather than individual species, such as parrots. Explain the advantages of conserving ecosystems.
0610_s17_qp_43
THEORY
2017
Paper 4, Variant 3
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Cheetahs, Acinonyx jubatus, are carnivores found in the dry grasslands and woodlands of southern Africa. Cheetahs hunt for food during the day. They eat deer and antelope. The cheetah is the fastest mammal on land but can only run at high speed over a short distance. Its hunting strategy is to creep up on prey and then sprint to catch them. is a photograph of a cheetah in its natural habitat. Suggest how these adaptive features enable cheetahs to survive in their natural environment. fur colouring streamlined body shape The king cheetah is a rare variety of A. jubatus that has inherited striped fur markings. shows a cheetah with spots and a king cheetah. cheetah with spots king cheetah Define the term inheritance. shows a pedigree diagram of a population of cheetahs. male king cheetah female king cheetah male cheetah with spots female cheetah with spots Key: ? Deduce the genotype of cheetah 11. Predict the probability of cheetah 14 being a king cheetah. Describe how a breeder could determine the genotype of cheetah 17. When the king cheetah was first discovered it was thought that it was a new species. Pedigree diagrams of cheetahs proved it was not a new species. Suggest one type of evidence, other than pedigree diagrams, that can be used to determine how closely related organisms are. Cheetahs are at risk of becoming endangered. Suggest why the cheetah is at risk of becoming endangered. Describe how species like the cheetah can be conserved.
0610_s20_qp_42
THEORY
2020
Paper 4, Variant 2
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Questions Discovered
99