Candidate Name Centre Number Candidate Number 0

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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.

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1. 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 Pollution Level

Mayfly nymph Clean

Caddis fly larva Low

Water louse High

Sludgeworm Very high

(a) What can you conclude from the results about the level of pollution in the

stream? Give your reasons. [3]

...

20

15

10

5 0 2000 2004 2008

Year

Numb er Sludge wo rm

Wate r lous e

Caddis fl y larva

Ma yfl y n ym ph

Sludge wo rm

Wate r louse

Caddis fl y larva

Ma yfl y n ym ph Ma yfl y n ym ph Caddis fl y larva Wate r louse Sludge wo rm

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(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]

...

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2. Seven types of foxes are listed below. Their scientific names are given next to their common names.

Common name Scientific name

Arctic fox Alopex lagopus

European fox Vulpes vulpes

Bat-eared fox Otocyon megalotis

Fennec fox Fennecus zerda

Sand fox Vulpes velox

Grey fox Urocyon cinereoargentus

Kit fox 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]

...

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3. 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]

...

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4. 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.

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The results were as follows:

Type of food

Energy content / kJ g

^-1

Apparatus A Apparatus B

Carbohydrate 10.3 19.3

Fat 21.0 28.0 Protein 10.4 19.3

(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]

...

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5. 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

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(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 1 27 8 2 24 7 3 32 11 4 74 24 5 17 6 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]

...

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6. 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)

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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]

...

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7. 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]

...

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(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) ...

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8. The diagram shows the flow of energy through a food chain in kilojoules per square

metre per year.

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(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 1 000 000 3000 0.3

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]

...

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9. 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]

...

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10. 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]

...

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(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.