20.4. Conservation
A subsection of Biology, 0610, through 20. Human influences on ecosystems
Listing 10 of 99 questions
Use The Ruddy duck, Oxyura jamaicensis, is a native of America. A flock of 20 birds was introduced into Britain from America before 1950. The original flock settled quickly in their new habitat and started breeding. Numbers now exceed 6000. The White-headed duck, Oxyura leucocephala, (a native of Spain) is a closely related species to the Ruddy duck. Female White-headed ducks are more attracted to male Ruddy ducks than to males of their own species. Cross-breeding between the two species produces a new variety of fertile duck. The White-headed duck is now threatened with extinction. Some conservationists are considering a plan to kill the British population of Ruddy ducks to prevent the White-headed duck becoming extinct. shows a male Ruddy duck. State two features, visible in , that distinguish birds, such as the Ruddy duck, from other vertebrate groups. With reference to an example from the passage, describe what is meant by the term binomial system. State two reasons, based on information in the passage, why the Ruddy duck and White-headed duck are considered to be closely related. Examiner's Use Explain why Ruddy ducks would not become extinct, even if British conservationists carried out their plan. Suggest one factor, other than the breeding habits of the Ruddy duck, that could result in the extinction of a bird such as the White-headed duck. The Ruddy duck feeds on seeds and insect larvae. The ducks are eaten by foxes and humans. Explain why these feeding relationships can be displayed in a food web, but not in a food chain.
0610_s05_qp_3
THEORY
2005
Paper 3, Variant 0
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For Examiner's Use The Galápagos Islands in the Pacific Ocean have many species of animals and plants that live nowhere else. Iguanas are large herbivorous reptiles. Four species of iguana live on the Galápagos Islands: • marine iguana, Amblyrhynchus cristatus • land iguana, Conolophus subcristatus • Santa Fe land iguana, Conolophus pallidus • pink land iguana, Conolophus rosada shows a marine iguana. Reptiles and mammals are both vertebrates. State three features of mammals that are not found in reptiles. For Examiner's Use The marine iguana, A. cristatus, feeds on seaweed and must therefore dive several metres into the cold waters that surround the Galápagos Islands. Iguanas can only stay in the water for a short length of time, until their body temperature drops too low. Mammals of an equivalent size, such as sea otters, can stay in cold water for a long time. Explain how some mammals are able to stay in cold water for a long time. Land iguanas live on Isabela, the largest island in the Galápagos. In 1986, some rangers from the Galápagos National Park found a population of pink land iguanas living at the northern end of the island. These iguanas have been studied in detail and are now classified as a new species, C. rosada. Define the term population. Suggest how a study of the DNA of iguanas helps to classify them. For Examiner's Use The International Union for the Conservation of Nature describes these iguanas as vulnerable. This means that their populations are likely to become extinct. Suggest two reasons why it is important to conserve individual species, such as the four species of iguana on the Galápagos Islands.
0610_s12_qp_31
THEORY
2012
Paper 3, Variant 1
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For Examiner's Use The red slender loris, Loris tardigradus, is a nocturnal mammal that feeds at night on flowers, fruit and a variety of small animals. It is found in forest ecosystems in South Asia. shows a red slender loris. Explain the meaning of the term ecosystem. State three ways in which mammals, such as the red slender loris, differ from other groups of vertebrates. For Examiner's Use The large eyes of the red slender loris show that it is well adapted for a nocturnal way of life. Suggest other features that the animal is likely to have that are adaptations to being active at night. Two species of slender loris are found in Sri Lanka, the grey slender loris, L. lydekkerianus, and L. tardigradus. The International Union for Conservation of Nature describes the red slender loris as endangered. Horton Plains National Park in Sri Lanka is one of the few places where L. tardigradus is found. Discuss why areas of land, such as the Horton Plains National Park, must be conserved. State how scientists could show that two populations of slender loris belong to the same species or to two different species.
0610_s12_qp_32
THEORY
2012
Paper 3, Variant 2
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F ig. 1.1 shows seven different species of amphibian. A B C D E F G not drawn to scale Use the key to identify each species. Write the letter of each species (A to G) in the correct box beside the key. One has been done for you. Key 1 long, narrow body, with or without legs go to 2 body not long and narrow, back legs are larger than the front legs go to 5 2 body without legs Gymnopis multiplicata B body with legs which are all of the same size go to 3 3 raised crest along the back of the body Triturus cristatus no crest along the back of the body go to 4 4 gills present Necturus maculosus no gills present Ambystoma tigrinum 5 skin is smooth go to 6 skin is not smooth Oreophrynella quelchii 6 digits end in swellings Polypedates leucomystax digits do not end in round swellings Rana temporaria Many amphibian species throughout the world are endangered. Suggest three reasons why many amphibian species are endangered.
0610_s15_qp_33
THEORY
2015
Paper 3, Variant 3
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Climate change is one reason why a plant species could become endangered. State other reasons why a plant species could become endangered. Describe how human actions are causing climate change. Seed banks are used to conserve endangered plant species. shows some of the steps involved in managing a seed bank. seeds are collected from many populations of each species seeds are checked using X-rays seeds are stored at low temperatures in the seed bank a small sample of seeds is germinated Explain why seeds from one species are collected from many populations to store in a seed bank. Seeds are X-rayed before they are stored to check that they contain an embryo. State one possible consequence of using ionising radiation on seeds. Seeds stored at low temperatures have very low respiration rates. Explain why. One purpose of seed banks is to reintroduce plant species into their natural environment. A survey was done to find out why some reintroduction programmes are not successful. shows the results of the survey. percentage of species that were not successfully reintroduced reason unknown wrong habitat changing habitat seeds did not germinate reasons why reintroductions failed seedlings too young too few individuals wrong season Some of the seeds in the reintroduction programmes did not germinate. State the conditions that are necessary for seeds to germinate. Some reintroduction programmes failed because the seedlings were too young. Young seedlings only have a few small roots. Explain why it would be important to reintroduce plants with many large roots. The low number of individuals also caused some reintroduction programmes to fail. State the name of the phase in a population growth curve where the number of individuals is very low.
0610_s21_qp_42
THEORY
2021
Paper 4, Variant 2
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There are three species of rhinoceros in Asia. shows an Indian rhinoceros, Rhinoceros unicornis, in a national park being observed by tourists who are riding on an elephant. The International Union for Conservation of Nature (IUCN) collects data on animal species and places them into categories based on estimated numbers. Table 4.1 summarises the conservation status of the three species of rhinoceros, as available in 2020. Table 4.1 species location approximate number in the wild approximate number in captivity IUCN category Indian rhinoceros Rhinoceros unicornis national parks in south Nepal and north India vulnerable Javan rhinoceros Rhinoceros sondaicus one national park in Java, Indonesia critically endangered Sumatran rhinoceros Dicerorhinus sumatrensis national parks in Sumatra and Borneo in Indonesia In 2013, Cincinnati Zoo in the USA announced that they were hoping to breed together rhinoceros that were brother and sister as part of their captive breeding programme. Discuss the problems that using such closely related animals might have for the conservation of rhinoceros. Captive breeding programmes often use artificial insemination. Outline the process of artificial insemination.
0610_s21_qp_43
THEORY
2021
Paper 4, Variant 3
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Questions Discovered
99