GCSE BITESIZE Examinations

Transcription

1 GCSE BITESIZE Examinations General Certificate of Secondary Education AQA SCIENCE A BLY1B Unit Biology B1b (Evolution and Environment) AQA BIOLOGY Unit Biology B1b (Evolution and Environment) FOUNDATION TIER Specimen Paper Time allowed: 30 minutes Maximum marks: 36 Instructions Answer all of the questions for the Tier you are attempting. Record your answers on a separate answer sheet only. Do all rough work in this book - not on your answer sheet. Advice Do not choose more responses than you are asked to. You will lose marks if you do. 1

2 FOUNDATION TIER SECTION ONE Questions ONE to FIVE In these questions, match the letters A, B, C and D with the numbers 1-4. Use each answer only once. Mark your choice on the answer sheet. QUESTION ONE Different living organisms reproduce in different ways. Match the words A, B, C and D with the numbers 1-4 in the sentences. A B C D gametes clones genes chromosomes The development of our characteristics is controlled by our 1. These are carried on strands of genetic material in the nucleus called 2. In sexual reproduction, each parent contributes half of their genetic material. To do this, they produce specialised cells called 3. Asexual reproduction involves one parent passing on all of their genetic material to produce genetically identical offspring. These offspring are known as 4. 2

3 QUESTION TWO As the population of humans grows, the impact we have on the environment increases. Match the words A, B, C and D with the numbers 1-4 in the sentences. A B C D sulfur dioxide methane fertiliser herbicide Farmers can speed up the growth of crops using 1., but this can cause water pollution. They can also speed up crop growth by using 2. to eliminate competition from other plants, but this can cause land pollution. Farmers are also growing more rice and rearing more cattle, which produces greater amounts of 3. and contributes to global warming. We are also burning fossil fuels, generating 4., which is largely responsible for producing acid rain. 3

4 QUESTION THREE The fennec fox lives in the desert. It is very dry there, and very hot during the day but cold at night. Fennec foxes have evolved adaptations to help them to survive in these conditions. Match the adaptations A, B, C and D with the explanations 1-4 in the table. A B C D Large ears Thick fur between pads of the feet Pale-coloured fur Reflective surface at the back of the eye Explanation 1 Increases the surface area through which heat can be lost. 2 Provides excellent vision at night. 3 Allows it to walk on the hot sand. 4 Reflects heat and acts as camouflage. 4

5 QUESTION FOUR This diagram shows how it may be possible to produce cloned animals by embryo transplantation: Match the statements A, B, C and D with the numbers 1-4 in the diagram. A B C D The embryos are transplanted into surrogate mothers. The offspring that are born are clones of each other. Each of the separated cells divides to form identical embryos. The embryo is split apart into separate cells. 5

6 QUESTION FIVE Scientists have studied the variety of life on Earth, looking for clues to its origin. Match the words A, B, C and D with the numbers 1-4 in the sentences. A B C D natural selection fossilisation mutation evolution Scientists believe that all life on Earth developed from simpler organisms 3.5 billion years ago. This theory is known as the theory of 1. Occasionally, the genes of some organisms changed by a process known as 2. This made these organisms better adapted than the others, so they survived to pass on their genes, while others died out. This is called 3., and has resulted in new species developing over millions of years. However, the remains of some of the ancient species were preserved by a process known as 4., which provides evidence for this theory. 6

7 SECTION TWO Questions SIX to NINE Each of these questions has four parts. In each part, choose only one answer. Mark your choices on the answer sheet. QUESTION SIX Scientists wanted to investigate the levels of water pollution along a river. They used the number of invertebrate species as a measure of pollution. To do this, the scientists chose six sites (one mile apart) along a river. They marked out a 1m 2 area at each site, and kicked the stones on the river bed within this area for three minutes. They used a one-metre net directly downstream of the sample area to catch any invertebrate species which were dislodged by the kicking. These species were then identified and counted. The results are shown in the diagram on the next page. 7

8 6A The number of each type of invertebrate species provides a measure of the pollution levels within the river. In this context, they are known as 1 monitor species. 2 indicator species. 3 dependent species. 4 endangered species. 8

9 6B In this experiment, what was the independent variable (the variable the scientists changed)? 1 The number of creatures the scientists collected. 2 The size of the area the scientists sampled. 3 The type of species the scientists collected. 4 The part of the river the scientists sampled. 6C Which site did the data indicate was most polluted? D This data would be best displayed using 1 a bar chart. 2 a line graph. 3 a pie chart. 4 a scattergram. 9

10 QUESTION SEVEN The graphs below show the carbon dioxide emissions of different countries in Figure 1 shows the total emissions of each country in billions of kg. Figure 2 shows the total emissions per person in each country in thousands of kg. 10

11 7A Using the information from Figure 1, how much more carbon dioxide is made by the United States than by the United Kingdom? 1 5,800 billion kg 2 5,400 billion kg 3 5,200 billion kg 4 5,000 billion kg 7B Figure 2 allows a more valid comparison between countries because... 1 the data is more reliable in Figure 2. 2 it has a smaller scale on the y axis. 3 it takes into account differences in the size of countries. 4 it takes into account differences in population size. 7C Emissions per person are lower in countries such as India than they are in the UK because: 1 They have a smaller population. 2 They have more energy-efficient technology. 3 They have a lower standard of living. 4 The emissions data from these countries is not reliable. 7D Sustainable development means continuing to improve our standard of living while conserving the planet and its resources for future generations. Which of these is not a method of achieving sustainable development? 1. Investing in the provision of public transport. 2. Converting more forest land into grazing land for cattle. 3. Providing local paper, glass and metal recycling facilities. 4. Investing in renewable energy resources. 11

12 QUESTION EIGHT A group of students carried out an investigation to determine whether the number of dandelions increased as the distance from trees increased. To do this, they set up a series of quadrats at regular one-metre intervals along a tape measure, beginning immediately next to the tree. They used a plastic grid with 25 squares on it to estimate the percentage of the quadrat that was covered by dandelions. They repeated their observations along another tape measure that was two metres to the right of the first. The table shows their results: Distance from tree (m) Percentage of quadrat covered by dandelions along tape measure Percentage of quadrat covered by dandelions along tape measure 2 12

13 8A Why did the students design their experiment in order to sample along two tape measures which were close together, instead of repeating the samples in different fields? 1 So that there results would be less likely to contain systematic errors. 2 So that they could easily identify a relationship between the distance and the percentage covered by dandelions. 3 So that variables which they were unable to control had the same effect on both sets of readings. 4 So that data could be collected with the same degree of precision. 8B What was the range of values observed in the dependent variable? 1 0 to 11 per cent 2 0 to 13 per cent 3 0 to 8 metres 4 0 to 1 metres 8C One of the students suggested that the trend could be explained in terms of competition, with there being greater competition nearer to the trees than further away from them. Which of these would the dandelions compete with the tree for? 1 Food 2 Territory 3 Mates 4 Nutrients 13

14 8D Which of these would improve the accuracy of the percentage cover measurements? 1 Using a plastic grid containing 100 smaller squares within the quadrat. 2 Taking readings every half a metre, instead of every metre. 3 Getting another group to repeat the same experiment, and comparing results. 4 Extending the measurements further from the tree. 14

15 QUESTION NINE Read the passage below: G.M. mosquito could fight malaria Malaria is a disease which is caused by a parasite. It is spread between humans by bites from mosquitoes, and kills more than 1 million people a year worldwide. A genetically modified (G.M.) strain of mosquito that is resistant to malaria has been created, and it is able to survive better than mosquitoes which carry the disease. The G.M. mosquito carries a gene that prevents infection by the malaria parasite. In experiments, equal numbers of G.M. and ordinary mosquitoes were allowed to feed on malaria-infected mice. As they reproduced, more of the G.M. mosquitoes survived. Adapted from a BBC News Online article, March A The results of the investigation were that, after nine generations, 70 per cent of the insects that survived belonged to the malaria-resistant strain. Scientists think this is because the malaria parasite reduces the health of infected mosquitoes, making them less able to compete against the malaria-resistant mosquitoes. This idea is 1 a hypothesis. 2 an experiment. 3 a theory. 4 a conclusion. 15

16 9B When scientists began this experiment, they chose large numbers of genetically modified (G.M.) and ordinary mosquitoes for the trial. This was important because 1 it improved the reliability of the experiment. 2 it improved the precision of the experiment. 3 it improved the accuracy of the experiment. 4 it improved the sensitivity of the experiment. 9C In the experiment, scientists also inserted a gene which made the eyes of the genetically modified (G.M.) mosquitoes glow green. The reason for this was 1 It allowed the G.M. mosquitoes to compete better than the wild type of mosquitoes. 2 It gave scientists a way to easily count which mosquitoes were genetically modified, and which were not. 3 It warned the parasite against infecting the G.M. mosquito. 4 It made it harder for the G.M. mosquitoes to survive. 9D Scientists hope that this research will eventually lead to G.M. mosquitoes being released into the environment on a large scale. The aim of doing this will be 1 to eliminate the spread of the malaria parasite between humans. 2 to prove that genetically modified organisms are safe. 3 to eliminate all mosquitoes in warm areas. 4 to protect crops from insect pests. END OF QUESTIONS 16