Biology Unit B1 Influences on Life'

Transcription

1 Biology Unit B1 Influences on Life' Study and Revision Pack (Foundation Paper) Content Page number B1 overview and assessment 2 tracking B1.1 Specification statements 3 B1.1 Exam Questions 5 B1.2 Specification statements 18 B1.2 Exam Questions 19 B1.3 Specification statements 29 B1.3 Exam Questions 31 Name: Form: 1

2 Overview and assessment tracking Please use the table below to keep track of your revision. Revision complete? Questions completed? Marks in first try % in first try Marks in second try % in second try B1.1 B1.2 B1.3 Use the grade boundaries below as a guide to the grade you are achieving: % Grade 60 C 50 D 40 E 30 F 2

3 Topic 1: Classification, variation and inheritance Current RAG B1.1 Specification statements B1 Specification Revised Demonstrate an understanding of how biologists classify organisms according to how closely they are related to one another including: a Species groups of organisms that have many features in common b Genus contains several species with similar characteristics c Family comprising of several genera d Order comprising of several families e Class comprising of several orders f Phylum comprising of several classes g The Five Kingdoms animalia, plantae, fungi, protoctista and prokaryota 1.2 Describe the main characteristics of the five kingdoms including: a Animalia multicellular, do not have cell walls, do not have chlorophyll, feed heterotrophically b Plantae multicellular, have cell walls, have chlorophyll, feed autotrophically c Fungi multicellular, have cell walls, do not have chlorophyll, feed saprophytically d Protoctista unicellular, have a nucleus e Prokaryota unicellular, have no nucleus 1.3 Explain why scientists do not classify viruses in any of the five kingdoms and regard them as non-living 1.4 Describe the main characteristics of the phylum Chordata as animals with a supporting rod running the length of the body, an example of this being the backbone in vertebrates 1.5 Explain how scientists place vertebrates into groups based on: a Oxygen absorption methods lungs, gills and skin b Reproduction internal or external fertilisation, oviparous or viviparous c Thermoregulation homeotherms and poikilotherms 1.6 Demonstrate an understanding of the problems associated with assigning vertebrates to a specific group based on their anatomy and reproduction methods and why many vertebrates are difficult to classify 1.7 Discuss why the definition of a species as organisms that produce fertile offspring may have limitations: some organisms do not always reproduce sexually and some hybrids are fertile 1.9 Explain how accurate classification may be complicated by variation within a species 1.10 Construct and use keys to show how species can be identified 1.11 Explain how organisms are adapted to their environment and how some organisms have characteristics that enable them to survive in extreme environments, including deep-sea hydrothermal vents and polar regions 3

4 1.12 Demonstrate an understanding of Darwin s theory of evolution by natural selection including: a variation most populations of organisms contain individuals which vary slightly from one to another b over-production most organisms produce more young than will survive to adulthood c struggle for existence because populations do not generally increase rapidly in size there must therefore be considerable competition for survival between the organisms d survival those with advantageous characteristics are more likely to survive this struggle e advantageous characteristics inherited better adapted organisms are more likely to reproduce successfully passing on the advantageous characteristics to their offspring f gradual change over a period of time the proportion of individuals with the advantageous characteristics in the population will increase compared with the proportion of individuals with poorly adapted characteristics, and the 1.13 Describe variation as continuous or discontinuous 1.14 Differentiate between longitudinal and transverse waves by referring to sound, electromagnetic and seismic waves 1.15 Interpret information on variation using normal distribution curves 1.16 Demonstrate an understanding of the causes of variation, including: a genetic variation different characteristics as a result of mutation or reproduction b environmental variation different characteristics caused by an organism s environment (acquired characteristics) 1.18 Explain how new evidence from DNA research and the emergence of resistant organisms supports Darwin s theory 1.19 Explain the role of the scientific community in validating new evidence, including the use of: a scientific journals b the peer review process c scientific conferences 1.20 Describe the structure of the nucleus of the cell as containing chromosomes, on which genes are located 1.21 Demonstrate an understanding that genes exist in alternative forms called alleles which give rise to differences in inherited characteristics 1.22 Recall the meaning of, and use appropriately, the terms: dominant, recessive, homozygous, heterozygous, phenotype and genotype 1.23 Analyse and interpret patterns of monohybrid inheritance using a genetic diagram, Punnett squares and family pedigrees 1.24 Calculate and analyse outcomes (using probabilities, ratios and percentages) from monohybrid crosses 1.25 Describe the symptoms of the genetic disorders: a sickle cell disease b cystic fibrosis 4

5 B1.1 Exam Questions- 78 marks, 78 minutes. Q1. Classification (a) Camels belong to the phylum Chordata. The drawing shows a dromedary camel that has the binomial name Camelus dromedaries. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The second part of the binomial name, dromedaries, refers to the A class B genus C order D species (ii) State one feature that all members of the phylum Chordata have in common. (iii) Members of the phylum Chordata can be further classified by how they regulate their body temperature. Reptiles are poikilothermic and mammals are homeothermic. Explain how reptiles and mammals regulate their body temperature. 5

6 (b) Scientists classify organisms into five different kingdoms. Draw one straight line from each description to its correct kingdom. (c) Viruses are not classified into any of the five kingdoms. Suggest reasons for this. 6

7 Q2. The photograph shows the mushroom, Russula silvicola. Russula silvicola is a multicellular organism that does not have chlorophyll. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. Russula silvicola belongs to the kingdom A Animalia B Fungi C Prokaryotes D Protoctista (ii) Russula silvicola is the binomial name of this mushroom. Draw one straight line from each part of the binomial name to its classification. 7

8 (b) State two characteristics of the kingdom Plantae. (c) (i) Vertebrates belong to the kingdom Animalia. Use words from the box to complete the following sentence. Vertebrates are members of the phylum and most have a running the length of the body. (ii) State the structures that vertebrate organisms use to absorb oxygen from their surroundings. (3) Q3. The photograph shows a bee collecting nectar from a flower. (Total for Question is 10 marks) (a) Nectar is made from glucose produced by plants. Name the process that plants use to make glucose. (b) (i) When the bee collects nectar from the flower, the plant benefits because the pollen sticks to the bee and is carried to another flower. Complete the sentence by putting a cross ( ) in the box next to your answer. The relationship between the bee and the plant is an example of A decomposing B eutrophication C mutualism D parasitism 8

9 (ii) Some bees have evolved a new method of collecting nectar from flowers. They drill a small hole in the base of the flower and collect the nectar through the hole. This means the pollen does not stick to the bee. Suggest why this is an advantage to the bees. (c) Bees can sting people. State the physical barrier of the human body that would have to be broken by the bee sting. (d) Honey produced by bees is a natural antiseptic. Describe how antiseptics can be used, during food preparation, to prevent the spread of infections. (e) Explain how the human body uses chemical defences to prevent infections. (3) (Total for Question is 10 marks) Q4. The photograph shows a single-celled bacterium. (a) (i) Complete the sentence by putting a cross ( Bacteria are classified into the kingdom ) in the box next to your answer. 9

10 A animalia B plantae C fungi D prokaryota (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. Bacteria do not contain A a cell membrane B a cell wall C a nucleus D chromosomes (b) Viruses are not classified into any kingdom. Describe what a virus does after it has entered its host. (c) All vertebrates have a backbone and are classified into groups. (i) Use words from the box to complete the sentences about one method of classification. Once fertilisation has occurred some vertebrates lay eggs. Vertebrates that lay eggs are known as Vertebrates that give birth to live young are known as (ii) Describe two other methods scientists can use to place vertebrates into groups. (Total for Question is 7 marks) 10

11 Q5. Variation (a) Scientists investigated one aspect of diet on the growth of six people. When the six people were babies, they had different masses of calcium in their diets. The height of each person was recorded when they were 10 and 18 years old. The results are shown in the table. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The person with the most growth between 10 and 18 years had a daily diet containing A 300 mg calcium per day B 700 mg calcium per day C 900 mg calcium per day D 1100 mg calcium per day (ii) Calculate the average rate of growth per year between the age of 10 and 18 for person 3. answer =...cm per year (iii) Describe the effect of the mass of calcium in the diet of a baby on their height at the age of 10 and 18. (3) (iv) Height can be illustrated by a normal distribution curve. Give the name of this type of variation. (b) Height can be due to environmental and genetic variations. State two causes of genetic variation. 11

12 Q6. The diagram shows a chromosome. (i) Use words from the box to complete the sentences. Chromosomes have sections which code for specific characteristics. Each characteristic is coded for by a These exist in alternative forms called (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. In a human body cell, chromosomes are found in the A cell membrane B cytoplasm C DNA D nucleus Q7. Sickle cell disease is a genetic disorder caused by recessive alleles. (i) State the meaning of the word allele. (ii) Human characteristics are coded for by genes. Describe where genes are found inside a human cell. 12

13 (iii) Complete the sentence by putting a cross ( ) in the box next to your answer. Sickle cell disease causes a change in the shape of the A lungs B pancreas C red blood cells D white blood cells Q8. (a) The diagram shows a human body cell. Name the structures labelled A and B. (b) Genes code for the characteristics of an individual. Different forms of the same gene are called alleles. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The term used to describe an individual with two identical alleles is A heterozygous B homozygous C dominant D recessive (ii) Blue eyes are an example of a person's physical characteristics. State the genetic term for a person's physical characteristics. (c) The diagram shows the inheritance of eye colour in a family. The allele for brown eyes is B and the allele for blue eyes is b. 13

14 (i) How many offspring have blue eyes? Put a cross ( ) in the box next to your answer. A 1 B 2 C 3 D 4 (ii) Explain why none of the children of Jason and Jane have the genotype BB. (iii) Fred has an identical twin. Explain which of the other children is Fred's identical twin. (3) (Total for Question is 10 marks) 14

15 Q9. Sickle cell disease Sickle cell disease is a genetic disorder caused by recessive alleles. (a) (i) State the meaning of the word allele. (ii) Human characteristics are coded for by genes. Describe where genes are found inside a human cell. (iii) Complete the sentence by putting a cross ( ) in the box next to your answer. Sickle cell disease causes a change in the shape of the A lungs B pancreas C red blood cells D white blood cells (b) The diagram shows a family pedigree for the inheritance of sickle cell disease. The recessive allele for sickle cell disease is (d) and the dominant allele is (D). (i) Explain why David and Alexandra do not show the symptoms of sickle cell disease. 15

16 (ii) Explain why there would be no children with sickle cell disease if one of the parents had the genotype DD. (b) Sickle cell disease is a genetic disorder that affects human red blood cells. Individuals with sickle cell disease have the genotype dd. (i) Draw one straight line from the genotype to the correct description. (ii) Describe the symptoms of sickle cell disease. 16

17 *(iii) A father with the genotype DD and a mother with the genotype dd for sickle cell disease had a number of children. Explain why none of their children will have sickle cell disease. Use a Punnett square or genetic diagram to help your explanation. (6) 17

18 Topic 2: Responses to a changing environment Current RAG Revised 1 Revised 2 Revised 3 B1.2 Specification statements B1 Specification 2.1 Define homeostasis as the maintenance of a stable internal environment 2.2 Demonstrate an understanding of the homeostatic mechanisms of: a thermoregulation and the effect of temperature on enzymes b osmoregulation c blood glucose regulation 2.3 Explain how thermoregulation takes place, with reference to the function of the skin, including: a the role of the dermis sweat glands, blood vessels and nerve endings, hair, erector muscles and sebaceous glands b the role of the hypothalamus regulating body temperature 2.5 Recall that hormones are produced in endocrine glands and are transported by the blood to their target organs 2.6 Explain how blood glucose levels are regulated by insulin and excess blood glucose is converted to glycogen in the liver 2.8 Recall that Type 1 diabetes is caused by a lack of insulin 2.9 Explain how Type 1 diabetes can be controlled, including the roles of diet and injection of insulin usually into the subcutaneous fat 2.10 Explain how, in Type 1 diabetes, the level of physical activity and diet affect the amount of insulin required 2.11 Recall that Type 2 diabetes is caused by a person becoming resistant to insulin 2.12 Explain how Type 2 diabetes can be controlled by diet and physical activity 2.13 Evaluate the correlation between obesity (including calculations of BMI) and Type 2 diabetes 2.14 Explain how plant growth substances (hormones) bring about: a positive phototropism in shoots b positive gravitropism (geotropism) in roots 2.15 Explain how auxins bring about shoot curvature using cell elongation 2.17 Analyse, interpret and evaluate data from plant hormone experiments, including the action of auxins and gibberellins 18

19 B1.2 Exam Questions- 81 marks, 81 minutes Q1. Body temperature A scientist investigated the effect of changes in external temperature on a person s internal body temperature. The graph shows the results of this investigation. (a) (i) Calculate the difference in internal body temperature between an external temperature of 20 C and 40 C. answer =... C (ii) Explain why it is important that body temperature does not rise above 40 C. (b) Complete the sentence by putting a cross ( ) in the box next to your answer. The maintenance of body temperature is an example of A conservation B homeostasis C hybridisation D mutualism (c) Explain how hair on the skin helps to maintain body temperature in a cold environment. 19

20 Q2. *(d) Blood glucose levels also need to be controlled. Describe how type 1 diabetes and type 2 diabetes are controlled. (6) Draw one straight line from the definition to the keyword. Q3. Complete the sentence by putting a cross ( The maintenance of body temperature is an example of A conservation B homeostasis C hybridisation D mutualism ) in the box next to your answer. 20

21 Q4. The diagram shows a sweat gland in a section of skin. (a) Explain how the sweat gland helps to cool the body. (b) Draw one straight line from the definition to the keyword. (c) (i) The hypothalamus is involved in regulating body temperature. Complete the sentence by putting a cross ( ) in the box next to your answer. The hypothalamus is part of the A brain B liver C lungs D pancreas 21

22 (ii) Explain how shivering can help a person regulate their body temperature. (iii) Describe how body hair helps to control a person's temperature on a cold day. Q5. The graph shows the blood glucose concentrations of two people, over an eight-hour period, after eating a meal. (a) (i) Describe the changes in blood glucose concentration for the person with diabetes. (ii) Calculate the difference in blood glucose concentration between the person with diabetes and the person without diabetes two hours after eating a meal. answer = mg per dm 3 22

23 (iii) In which two-hour period did the blood glucose concentration change the most for the person with diabetes? Put a cross ( ) in the box next to your answer. A 0 2 hours B 2 4 hours C 4 6 hours D 6 8 hours (b) Name the organ that releases insulin to regulate blood glucose concentrations. Q6. The glucose content of human blood also needs to be controlled. After a meal, high in carbohydrates, the glucose content of the blood will rise. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The hormone that lowers the glucose content of the blood is A auxin B glycogen C insulin D pancreas (ii) Explain how the glucose content of the blood can be decreased by this hormone. (iii) People with Type 1 diabetes cannot produce the hormone needed to control the glucose content of the blood. Explain how a Type 1 diabetic can control the glucose content of the blood.... (3) 23

24 Q7. Homeostasis If a person is to survive, the internal environment of their body must be controlled. (a) The volume of water in the blood can be controlled. This is called osmoregulation. The table shows the volume of urine produced by six different people on a hot day and on a cold day. person volume of urine produced / cm 3 hot day cold day mean 1000 (i) Calculate the mean volume of urine produced on the hot day. answer = cm 3 (ii) State the difference between the mean volume of urine produced on the hot day and the mean volume of urine produced on the cold day. (iii) Explain why, on a hot day, less water is lost from the body as urine. (b) The glucose content of human blood also needs to be controlled. After a meal, high in carbohydrates, the glucose content of the blood will rise. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The hormone that lowers the glucose content of the blood is A auxin B glycogen C insulin D pancreas (ii) Explain how the glucose content of the blood can be decreased by this hormone. 24

25 (iii) People with Type 1 diabetes cannot produce the hormone needed to control the glucose content of the blood. Explain how a Type 1 diabetic can control the glucose content of the blood. Q8. (3) People with diabetes have difficulties regulating their blood glucose concentration. The graph shows the percentage of the population with Type 2 diabetes between 1993 and (a) (i) Describe the overall trend shown in the graph. (ii) Calculate the change in the percentage of the population with Type 2 diabetes between 1993 and

26 (b) People who are obese can develop Type 2 diabetes. (i) Body Mass Index (BMI) can be used to indicate obesity. Complete the sentence by putting a cross ( ) in the box next to your answer. BMI is calculated using A mass only B height only C mass and height D mass and blood glucose (ii) Suggest why people with a high BMI may develop Type 2 diabetes. *(c) Describe the different methods that people with Type 1 diabetes and Type 2 diabetes use to regulate their blood glucose concentrations. (6) Q9. *Plant hormones affect the way plants grow. Explain how growth hormones cause phototropism and gravitropism in plants. (6) 26

27 Q10. Reaction times (a) The reaction times of some athletes were measured at the Beijing Olympics in the final of the 100 metres sprint. athlete reaction time / s overall race time / s Bolt: Usain Burns: Marc Dix: Walter Frater: Michael Martina: Churandy Patton: Darvis Powell: Asafa Thompson: Richard (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The athlete with the slowest reaction time is A Bolt: Usain B Martina: Churandy C Patton: Darvis D Thompson: Richard (ii) Name the athlete who finished the 100 metres sprint in the fastest time. (iii) Calculate the difference between the overall race time of the fastest athlete and slowest athlete. answer = s (b) The athlete starts to run when a gun is fired. (i) State the athlete's sense organ that detects this stimulus. (ii) Describe the nerve pathway a nerve impulse will take from where it is received to where it will cause a response to take place. (3) 27

28 Q11. Drugs can affect a person's nervous system. (a) (i) Complete the sentence by putting a cross ( Alcohol is classed as a ) in the box next to your answer. A depressant B hallucinogen C painkiller D stimulant (ii) State the effect alcohol has on the time taken to respond to a stimulus. (iii) Drinking excess alcohol over a long period of time can result in alcoholism. Suggest two long-term effects of alcoholism in the human body. (b) Some people drink coffee containing caffeine after drinking alcohol. Describe the effects of caffeine on the nervous system. *(c) The diagram shows the structure of a motor neurone. Explain how the structure of the motor neurone relates to its function in carrying messages through the nervous system. (6) 28

29 Topic 3: Problems of, and solutions to a changing environment Current Revised Revised Revised B1.3 Specification statements B1 Specification 3.1 Define a drug as a chemical substance, such as a narcotic or hallucinogen, that affects the central nervous system, causing changes in psychological behaviour and possible addiction 3.2 Describe the general effects of: a painkillers that block nerve impulses, including morphine b hallucinogens that distort sense perception, including LSD c stimulants that increase the speed of reactions and neurotransmission at the synapse, including caffeine d depressants that s 3.4 Explain the effects of some chemicals in cigarette smoke, including: a nicotine as an addictive drug b tar as a carcinogen c carbon monoxide reducing the oxygen-carrying ability of the blood 3.5 Evaluate data relating to the correlation between smoking and its negative effects on health 3.6 Evaluate evidence of some harmful effects of alcohol abuse: a in the short term blurred vision, lowering of inhibitions, slowing of reactions b in the long term liver cirrhosis, brain damage 3.7 Discuss the ethics of organ transplants, including: a liver transplants for alcoholics b heart transplants for the clinically obese c the supply of organs 3.8 Recall that infectious diseases are caused by pathogens 3.9 Describe how pathogens are spread, including: a in water, including cholera bacterium b by food, including Salmonella bacterium c airborne (eg sneezing), including influenza virus d by contact, including athlete s foot fungus e by body fluids, including HIV f by animal vectors, including: i housefly: dysentery bacterium ii Anopheles mosquito: malarial protozoan 3.10 Explain how the human body can be effective against attack from pathogens, including: a physical barriers skin, cilia, mucus b chemical defence hydrochloric acid in the stomach, lysozymes in tears 3.11 Demonstrate an understanding that plants produce chemicals that have antibacterial effects in order to defend themselves, some of which are used by humans 3.12 Describe how antiseptics can be used to prevent the spread of infection 3.13 Explain the use of antibiotics to control infection, including: a antibacterials to treat bacterial infections b antifungals to treat fungal infections 3.16 Recall that interdependence is the dynamic relationship between all living things 3.17 Demonstrate an understanding of how some energy is transferred to less useful forms at each trophic level and this limits the length of a food chain 3.18 Demonstrate an understanding that the shape of a pyramid of biomass is determined by energy transferred at each trophic level 29

30 3.19 Explain how the survival of some organisms may depend on the presence of another species: a parasitism, including: i fleas ii head lice iii tapeworms iv mistletoe b mutualism, including: i oxpeckers that clean other species ii cleaner fish 3.20 Analyse, interpret and evaluate data on global population change 3.21 Explain how the increase in human population contributes to an increase in the production of pollutants, including phosphates, nitrates and sulfur dioxide (acid rain) 3.22 Explain how eutrophication occurs and the problems associated with eutrophication in an aquatic environment 3.24 Demonstrate an understanding of how scientists can use the presence or absence of indicator species as evidence to assess the level of pollution: a polluted water indicator bloodworm, sludgeworm b clean water indicator stonefly, freshwater shrimps c air quality indicator lichen species, blackspot fungus on roses 3.25 Demonstrate an understanding of how recycling can reduce the demand for resources and the problem of waste disposal, including paper, plastics and metals 3.26 Demonstrate an understanding of how carbon is recycled: a during photosynthesis plants remove carbon dioxide from the atmosphere b carbon compounds pass along a food chain during respiration organisms release carbon dioxide into the atmosphere d decomposers release carbon dioxide into the atmosphere e combustion of fossil fuels releases carbon dioxide into the atmosphere 30

31 B1.3 Exam Questions- 92 marks, 92 minutes. Q1. Disease (a) The female mosquito can carry the Plasmodium protoctist. This protoctist causes malaria in humans. When the female mosquito breaks the skin of a person the Plasmodium is transferred into the blood of that person. (i) State the name of this type of disease transmission. (ii) The survival of the Plasmodium is dependent on living in the blood of another species. This relationship is an example of (iii) Plasmodium causes an infectious disease. What is the name given to any disease causing organism? Put a cross ( ) in the box next to your answer. A bacterium B lysozyme C pathogen D virus (b) The housefly can also carry disease causing organisms. Describe how the housefly spreads disease. (c) (i) State one physical barrier, in the human body, that helps prevent disease. (ii) Describe one chemical barrier, in the human body, that helps prevent disease. 31

32 Q2. The pie chart shows the causes of death of people who smoked tobacco. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. People who smoke tobacco are most likely to die from A chronic bronchitis and emphysema B heart disease C cancer D other causes including stroke (ii) The pie chart is based on a sample of 5000 people who smoked tobacco. Calculate how many of these people died from chronic bronchitis and emphysema. (iii) Explain how smoking tobacco can cause cancer. (b) (i) Caffeine is a type of drug. Complete the sentence by putting a cross ( ) in the box next to your answer. Caffeine is a A depressant B hallucinogen C painkiller D stimulant (ii) Describe the effect caffeine can have on the human body. 32

33 Q3. Drugs (a) The graph shows the number of alcohol-related deaths in Britain in four age ranges. (i) Which age range has the highest number of alcohol-related deaths in Britain? Put a cross ( ) in the box next to your answer. A B C D 75+ (ii) Describe the trend shown for alcohol-related deaths in the age range years. (iii) Suggest one reason for the reduction in alcohol-related deaths between 2008 and 2009 for year olds. (b) State the two organs in the body most affected by long term alcohol abuse (c) Explain the effect that alcohol has on the speed of reactions. 33

34 (d) A drug has been developed which blocks the feel good effects of drinking alcohol. Suggest why this may be beneficial to people with alcoholism. (e) Suggest one reason why some people disagree with alcoholics being given organ transplants. Q4. The diagram shows the numbers and biomass of organisms in a food chain. (a) (i) Calculate the difference in biomass between the aphids and the ladybirds. (ii) Energy is lost between each trophic level of a food chain. Suggest how this energy is lost between each trophic level. (iii) The diagram shows a pyramid of numbers for this food chain. In the box, draw a pyramid of biomass for this food chain. 34

35 (b) (i) Carbon can be recycled in the environment. State the name of the process in which plants remove carbon dioxide from the atmosphere. *(ii) Explain how the recycling of paper and plastics can benefit the environment. (6) Q5. Cholera is a disease caused by a pathogen. (a) (i) State the type of pathogen that causes cholera. (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. The cholera pathogen is spread A in air B by houseflies C by mosquitoes D in water 35

36 (b) The maps of the world show areas where there were cases of cholera recorded, from 1950 to The areas where cholera was recorded are shaded in black. (i) Describe the trend in the recorded cases of cholera shown in the maps. (ii) Suggest two reasons for this trend. (c) Explain how the physical barriers of the body can help to prevent infection by pathogens. (d) State the names of two chemicals that can be used to control infection. (3) 36

37 Q6. Survival (a) The photograph shows a crocodile holding its mouth open to allow a crocodile bird to feed. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. This type of symbiotic relationship between two organisms is known as A eutrophication B mutualism C parasitism D tropism (ii) Suggest why this relationship is beneficial to the crocodile. (b) (i) The crocodile and crocodile bird are members of food chains in a habitat. State the type of organism that is found at the start of most food chains. (ii) A crocodile can feed on fish. The diagram shows a pyramid of numbers for this feeding relationship. Draw, on the grid above, a pyramid of biomass for this feeding relationship. 37

38 *(c) Using examples, explain how the survival of parasites depends on the presence of other species. (6) Q7. (a) The graph shows some materials recycled in 2004 and 2010 (i) Calculate the increase in the mass of paper recycled between 2004 and (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. From the graph, the material that is recycled the least is A glass B paper C plastic D wood (iii) Suggest one reason why a large mass of paper is recycled. 38

39 (b) Composting is a method used to recycle waste from the garden and kitchen. Explain how composting increases carbon dioxide concentration in the air. (c) Explain how one other human activity contributes to an increase in carbon dioxide concentration in the air. Q8. Pollution (a) As the human population increases, more fossil fuels are burned. The burning of coal is one of the main contributors to acid rain. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The gas produced when coal burns that can lead to acid rain formation is A carbon monoxide B methane C oxygen D sulfur dioxide (ii) Describe how acid rain is formed. (iii) Suggest one effect acid rain has on the environment. (b) Explain how the quality of a river can be monitored by studying the organisms present in the water. 39

40 *(c) Eutrophication can cause problems in an aquatic environment such as a lake. Explain how eutrophication occurs and the problems it can cause in an aquatic environment. (6) Q9. Mistletoe plants The photograph shows a mistletoe plant growing on a tree. The mistletoe plant uses nutrients from the tree. This can cause the tree to die. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The relationship between the mistletoe plant and the tree is an example of A mutualism B parasitism C phototropism D symbiosis (ii) The mistletoe plant also gains energy from sunlight to produce glucose. State the name of this process. (b) The mistletoe plant produces fruit that contains seeds. The Mistle Thrush is a bird that spreads these mistletoe seeds to other trees. (i) Suggest how the Mistle Thrush spreads the mistletoe seeds to other trees. 40

41 (ii) Sparrowhawks are birds that are predators of the Mistle Thrush. The diagram shows the energy values in the food chain for these organisms. Calculate the percentage of energy that was passed from the mistletoe plant to the Mistle Thrush. answer = % (iii) Draw a pyramid of energy for this food chain. (iv) Suggest two ways in that energy is lost from this food chain. 41