GCSE (9 1) Combined Science (Biology) A (Gateway Science) J250/02 Paper 2, B4 B6 and CS7 (PAGs B1 B5)

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1 Oxford Cambridge and RSA GCSE (9 1) Combined Science (Biology) A (Gateway Science) Paper 2, B4 B6 and CS7 (PAGs B1 B5) (Foundation Tier) F Year 11 Test Time allowed: 1 hour 10 minutes You must have: a ruler (cm/mm) You may use: a scientific or graphical calculator an HB pencil First name Last name Centre number Candidate number INSTRUCTIONS Use black ink. You may use an HB pencil for graphs and diagrams. Complete the boxes above with your name, centre number and candidate number. Answer all the questions. Write your answer to each question in the space provided. Additional paper may be used if required but you must clearly show your candidate number, centre number and question number(s). INFORMATION The total mark for this paper is 60. The marks for each question are shown in brackets [ ]. Quality of extended response will be assessed in the questions marked with an asterisk (*). This document consists of 20 pages. DC (KN/TP) /4 OCR is an exempt Charity Turn over

2 2 SECTION A Answer all the questions. You should spend a maximum of 20 minutes on this section. 1 Which element is taken from the atmosphere during photosynthesis? A B C D Carbon Helium Nitrogen Potassium Your answer 2 The rate of decay of a slice of bread can be calculated by the change in mass over time. A slice of bread has a mass of 30 g. After 20 days of decay the mass is 20 g. Calculate the rate of decay. A B C D 0.25 g/day 0.50 g/day 1.00 g/day g/day Your answer

3 3 3 A sperm cell of a horse has 32 chromosomes. Number of chromosomes Horse egg cell Horse eye cell A B C D Which row in the table shows the correct number of chromosomes in each cell? Your answer 4 The height of a pea plant is controlled by one pair of alleles. The allele for tall (T) is dominant over the allele for dwarf (t). Genotype Phenotype A tt Dwarf B Tt Dwarf C Tt Tall D TT Tall Which row in the table describes a plant that is heterozygous for this characteristic? Your answer 5 Which two diseases interact with each other? A B C D HIV and cervical cancer HIV and HPV HIV and tuberculosis Tuberculosis and cervical cancer Your answer Turn over

4 4 6 A student collects data on two types of variation in humans. Height Weight A Bar graph Bar graph B Bar graph Line graph C Line graph Bar graph D Line graph Line graph Which are the most suitable graphs to use for height and for weight? Your answer 7 Mutations change the structure of molecules made inside cells. Which of these molecules are changed by mutations? A B C D Carbohydrates Fats Proteins Vitamins Your answer

5 5 8 The graph shows the percentage of adults of different ages that exceed the recommended intake of alcohol Percentages (%) and over Males and over Females Which group increased their risk of diseases associated with alcohol the most between 1988 and 2002? A Females aged 18 to 24 B Females aged 65 and over C Males aged 18 to 24 D Males aged 45 to 64 Your answer 9 The gene for flower colour has two alleles. Purple (P) is dominant over white (p). A genetic cross between two plants, both Pp, produces 160 offspring. How many of these offspring would you expect to be purple? A 40 B 80 C 120 D 160 Your answer Turn over

6 10 Which of the following does not fit with modern ideas on evolution? 6 A B C D Characteristics that do not help organisms can disappear from the population. Future generations contain organisms that are better suited to their environment. Offspring inherit characteristics from their parents. Organisms change during their lifetime and always pass these changes on to their offspring. Your answer

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8 8 SECTION B Answer all the questions. 11 Look at the photograph of a microscope slide showing blood cells. X (a) Cell X is adapted for defending the body. (i) Write down the name of cell X.... (ii) Describe how cell X defends the body.... [2]

9 (b) The diagram shows HIV, the microbe that causes AIDS. 9 Antigen (i) Which medicine is used to treat HIV? Put a ring around the correct answer. Antibiotic Antibody Antiseptic Antiviral (ii) The graph shows how many people died of AIDS related deaths, from 1990 to Number of deaths (million) Year Use the graph to suggest which year the medicine used to treat HIV was first introduced.... Turn over

10 10 (c) (i) Scientists are trying to make a vaccine against HIV. What might the vaccine contain?... (ii) Use ideas about immunity to explain how vaccines work.... [3] (d) Scientists are investigating the use of adult stem cells to treat HIV. Less people object to the use of adult stem cells than they do embryonic stem cells. Write down one reason why

11 12 (a) The diagram shows the different levels of organisation in an ecosystem. 11 Complete the diagram to show the missing levels. Organism Ecosystem [2] (b) (i) Caterpillars feed on the leaves of the horse chestnut tree. Scientists can measure the percentage damage the caterpillar causes to the leaves. Show how they would calculate the percentage damage of one leaf. Include the measurements they would take and the calculation they would make.... [2] Turn over

12 12 (ii) Measuring every leaf in a field study would take too long. Instead scientists estimate the damage using a damage scale. The picture shows a damage scale for horse chestnut leaves. 0 0% 1 2% 2 5% 3 10% 4 25% 5 50% 6 75% 7 100% Using the scale to collect data is better than making an estimate without it. Suggest two reasons why.... [2] (c) (i) Damage by the caterpillar does not kill the tree. The tree can be attacked for a long time and still survive. Complete the sentences. Choose words from the list. host mutualism pathogen parasite parasitism prey predator The feeding relationship between the tree and caterpillar is called.... The tree is the... and the caterpillar is the.... [2] (ii) The caterpillar eats through the palisade layer of the leaf removing many chloroplasts. How will the damage caused by the caterpillar affect the tree?... [2]

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14 14 13 Look at the picture of a great crested newt. The great crested newt is endangered and needs protecting. Anyone found guilty of harming the newt is fined or sent to prison. In the past, if newts were found on a building site the builders had to apply for a license from government to disturb the newts. The builders had to do an expensive and time consuming population survey. They also had to build an alternative habitat and move the newts. Local Planning Authority can now test ponds quickly for the DNA of great crested newts. Builders can then be guided to areas without great crested newts. This means now only the Local Planning Authority needs a license. (a)* Explain why a license is needed for building sites and what the benefits are of DNA testing ponds for the conservation of the great crested newt [6]

15 15 (b) (i) All great crested newts have the binomial name Triturus cristatus. Explain why DNA could be used to identify a great crested newt.... [2] (ii) Newts need food to survive. Their food contains proteins, lipids and carbohydrates. Complete the sentence about lipids. Choose words from the list. amino acids fatty acids glucose glycerol starch Lipids are digested by enzymes. The enzymes break the lipids down into... and.... [2] Turn over

16 16 14 Barnacles are animals that live on rocks on a shoreline. Barnacles are stuck to the rocks. They stay in one place for a long time. A student investigates two types of barnacles, rock barnacles and stellate barnacles. (a) The student uses sampling equipment to measure the number of barnacles on a shoreline. (i) Which type of sampling equipment is the most suitable to use? Explain why.... [2] (ii) Explain how the student uses the sampling equipment to estimate the barnacle population.... [3]

17 17 (b) The student finds differences between the distribution of stellate barnacles and rock barnacles. The diagram shows the distribution of stellate and rock barnacles. Highest tide Stellate barnacle Lowest tide Rock barnacle Rock barnacles find it hard to survive when their bodies dry out. Rock barnacles are better at feeding and attaching to rocks than stellate barnacles. Write down how these abiotic and biotic factors can explain the distribution of these two types of barnacles [2] (c) Global warming may cause sea levels to rise. This means high tides will occur higher up the rocky shore. Rising sea levels might reduce the stellate barnacle population. Suggest one reason why Turn over

18 18 15 The use of antibiotics has resulted in an increase in bacteria that are resistant to certain antibiotics. The table shows data for the percentage incidence of MRSA resistant bacteria. Year % Incidence (a) (i) Plot a graph to show the % incidence of MRSA over time. Draw a line of best fit. [4] (ii) The percentage incidence for 1990 is missing from the table. Use the graph to predict the percentage incidence for Answer =...%

19 19 (iii) How does evidence in the graph support the theory of evolution through natural selection?... [3] (b) (i) Bacterial cells are different to animal cells because they contain plasmids. Write about two other ways bacterial cells are different [2] (ii) A single plasmid may contain information on resistance to many different antibiotics. In the last few decades, doctors have been asked to prescribe less antibiotics to avoid further resistance developing. Very few new drugs have been developed in the last few decades. Suggest two reasons why.... [2] END OF QUESTION PAPER

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