Candidate Name Centre Number Candidate Number. HIGHER TIER (Grades D-A*)

Transcription

1 GCSE in SCIENCE A Specimen Assessment Materials 27 Candidate Name Centre Number Candidate Number 0 GCSE SCIENCE A HIGHER TIER (Grades D-A*) BIOLOGY 1 Adaptation, evolution and body maintenance SPECIMEN PAPER (1 hour) INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top of this page. Answer all questions. Write your answers in the spaces provided in this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. You are reminded that assessment will take into account the quality of written communication used in your answers to questions 3 and 11.

2 GCSE in SCIENCE A Specimen Assessment Materials In 2008 some year 11 students investigated the level of pollution in a stream running through a small town in South Wales. They had the information in Table A. They sampled a 10 m length of the stream for the presence of four indicator species. Their results are shown in the bar chart below, along with earlier results from the same stream. Table A Indicator species Mayfly nymph Caddis fly larva Water louse Sludgeworm Pollution Level Clean Low High Very high 20 Number Mayfly nymph Caddis fly larva Water louse Sludgeworm Mayfly nymph Caddis fly larva Water louse Sludgeworm Mayfly nymph Caddis fly larva Water louse Sludgeworm Year (a) What can you conclude from the results about the level of pollution in the stream? Give your reasons. [3]

3 GCSE in SCIENCE A Specimen Assessment Materials 29 (b) Nona said that these samples should be taken at the same time each year but Rhys said it doesn t matter. State who you think is right, giving a reason. [1] (c) State one other non-biological factor that could be measured and used as an indicator of the level of pollution in the stream. [1]...

4 GCSE in SCIENCE A Specimen Assessment Materials Seven types of foxes are listed below. Their scientific names are given next to their common names. Common name Arctic fox European fox Bat-eared fox Fennec fox Sand fox Grey fox Kit fox Scientific name Alopex lagopus Vulpes vulpes Otocyon megalotis Fennecus zerda Vulpes velox Urocyon cinereoargentus Vulpes ruppelli (a) State three foxes which you would expect to have the most similar DNA. [1] (b) In the 18 th century Carl Linnaeus developed the system of giving all living organisms a two word scientific name. How does this system help scientists in different countries who are studying these animals? [1]

5 GCSE in SCIENCE A Specimen Assessment Materials The diagram shows a section through the skin. Describe and explain how the blood vessels and sweat glands help to control body temperature in hot conditions. [6 QWC]

6 GCSE in SCIENCE A Specimen Assessment Materials An investigation was carried out into the energy content of three different types of foods using apparatus A and apparatus B. The change in temperature of the water was measured using a thermometer in A and B. The rise in temperature was used to calculate the energy released by the food, in kilojoules.

7 GCSE in SCIENCE A Specimen Assessment Materials 33 The results were as follows: Energy content / kj g -1 Type of food Apparatus A Apparatus B Carbohydrate Fat Protein (a) Use the diagram to explain the higher numbers in the results for apparatus B. [3] (b) Why is it important to the health of people that the labels on food containers give information about energy content? [1]

8 GCSE in SCIENCE A Specimen Assessment Materials Gregor Mendel made important discoveries on how characteristics or traits are passed from parents to offspring. In one of his experiments he crossed pea plants that produced seeds with round coats with plants that produced seeds with wrinkled coats. The result of this cross were plants (F1) that only produced round coated seeds. Mendel explained this by saying that pea plants passed on factors (alleles) from one generation to the next. He also said the factor for round seeds is dominant over the factor for wrinkled seeds. Use the information in the passage and your knowledge to answer the following questions. (a) The following shows how the F1 plants were produced in Mendel's experiment where: R = allele for round seeds r = allele for wrinkled seeds Complete the Punnett square to show the genotypes produced in this cross. [2] F1 gametes

9 GCSE in SCIENCE A Specimen Assessment Materials 35 (b) (i) Mendel then crossed two of these F1 plants together. Draw your own Punnett square and complete it to show the genotypes of the offspring that would be produced. [2] (ii) What is the ratio of round to wrinkled seeds produced above? [1]... round:... wrinkled (iii) When Mendel carried out the cross shown on the previous page he repeated the experiment hundreds of times. These are some of the results he obtained: Experiment number Number of seeds obtained Round Wrinkled How do the results of Mendel's experiments compare to your answer in (b)(ii)? [1] (c) Why was the importance of Mendel's discovery about inheritance not recognised until long after his death? [1]

10 GCSE in SCIENCE A Specimen Assessment Materials Bovine tuberculosis (btb) is a very serious disease of cattle in Britain. It is caused by a bacterium. There is very strong evidence of a link between btb in cattle and btb in badgers. The arrows in the following diagram show the ways in which btb can be transferred. The Government asked scientists to investigate whether the culling (controlled killing) of badgers would reduce the number of cases of btb in cattle herds. These are the conclusions of two of the reports: "badger culling can make no meaningful contribution to btb control in Britain" (Bourne Report 2007) "the removal of badgers could make a significant contribution to the control of btb..." (King Report 2007)

11 GCSE in SCIENCE A Specimen Assessment Materials 37 Study the diagram opposite and suggest one reason why: (a) the Bourne report concluded that culling badgers would have no effect on btb control; [1] (b) the King report concluded that culling badgers would have an effect on btb control. [1] (c) Using the information, suggest why some organisations object to the culling of badgers in an attempt to control btb. [1]

12 GCSE in SCIENCE A Specimen Assessment Materials The map shows the main pollution levels in some rivers which enter the North Sea. (a) Use the data on the map to suggest how agriculture and industry cause water pollution. (i) Agriculture [1] (ii) Industry [1]

13 GCSE in SCIENCE A Specimen Assessment Materials 39 (b) (i) In which river would you expect to have the lowest concentration of oxygen? [1]... (ii) Explain, in detail, why this river would have the lowest concentration of oxygen. [4] (c) It was noted that many birds that eat fish have been found dead near the mouth of the rivers Elbe and Rhine. Suggest two possible reasons for the death of these birds. [2] (i) (ii)

14 GCSE in SCIENCE A Specimen Assessment Materials The diagram shows the flow of energy through a food chain in kilojoules per square metre per year.

15 GCSE in SCIENCE A Specimen Assessment Materials 41 (a) Some energy is lost at points A and B. State two ways in which this energy could be lost. [2] (i) (ii) (b) Complete the table by calculating the percentage efficiency, of energy transferred, from the barley to the cow. Organism Energy received (kjm -2 y -1 ) Energy passed on (kjm -2 y -1 ) Percentage efficiency of energy transferred Barley Cow [1] (c) Explain why it would be more efficient for humans to eat barley rather than meat from cows. [3] (d) Suggest one disadvantage to humans of eating a diet of barley only. [1]

16 GCSE in SCIENCE A Specimen Assessment Materials Warfarin has been used as a poison to kill rats which compete with humans for stored grain. (a) In 1959, Warfarin-resistant animals appeared in Welshpool in mid-wales and began to spread. The spread of Warfarin resistance between 1967 and 1970 is shown in the map below. Explain how Warfarin resistance has increased. [4] (b) Suggest how the development of Warfarin resistance can be used to support Charles Darwin's theory of evolution. [2]

17 GCSE in SCIENCE A Specimen Assessment Materials Some plants, like the pitcher plant shown below, collect rain water in their modified cup-like leaves. Insects and small frogs collect in the water. The dead and decaying insects and other animals contain protein. The frogs which live in the water excrete urea. (a) Use your knowledge of the nitrogen cycle to explain how nitrate, used by the plant, can be produced in the water in the cup-like leaves. [3]

18 GCSE in SCIENCE A Specimen Assessment Materials 44 (b) Scientists have investigated the processes taking place in the cup-like leaves. They took samples of liquid from the cup-like leaves and added them to urea in two specimen tubes as shown in the diagrams. The specimen tubes were kept at 25 C for 12 hours. At the start of the investigation the indicator paper in both specimen tubes was yellow. After 12 hours, the indicator paper in A was green, but in B it was still yellow. (i) Explain how the results for tube B suggest that an enzyme was responsible for the change in tube A. [1] (ii) Suggest the type of organism which could produce the enzyme which acted on the urea. [1]...

19 GCSE in SCIENCE A Specimen Assessment Materials Describe and explain how negative feedback mechanisms regulate the level of glucose in the blood. [6 QWC]