VP*(S10-235-02)
ADDITIONAL MATERIALS
In addition to this paper you may require a calculator and a ruler.
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 of the necessity for good English and orderly presentation in your answers.
GCSE 235/02 SCIENCE
HIGHER TIER BIOLOGY 1
P.M. WEDNESDAY, 9 June 2010 45 minutes
For Examiner’s use only
3 3
1 6
2 6
5 4
4 6
7 9
6 2
Total 50
8 5
9 4
10 5
Question Maximum Mark
Mark Awarded
Name Number Number
0
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Answer all questions.
1. When Mendel crossed purple flowered pea plants with white flowered pea plants all the offspring (F1) were purple flowered.
(a) (i) Using the letters R and r to represent the alleles, complete the following
genotypes: [1]
purple flowered pea plant . . . . X white flowered pea plant . . . .
(ii) Complete the Punnett square to show the cross between the purple and white
flowered plants. [2]
Gametes
F1
(b) Construct a Punnett square in the space below to show how two pea plants when crossed together could produce 50% purple flowered and 50% white flowered plants. [2]
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(c) Mendel carried out his experiments on inheritance in the mid 1800s but the importance of his work was not recognised or understood for another 70 years. In the list below underline the statement that best describes the reason for this. [1]
Mendel didn’t publish his work
DNA and genes hadn’t been discovered
Mendel’s experiments were badly designed
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(235-02) 6 2. There is strong evidence that smoking bans are helping to reduce the levels of heart disease
caused by tobacco smoke.
The table shows the number of patients admitted with heart attacks to hospitals run by some Welsh National Health Service Trusts (NHS trusts) between 2005 and 2007.
NHS trust Number of patients admitted with heart attacks
2007 4029 2662 1701 2764 2514
% change between 2005 and 2007
Abertawe Bro Morgannwg
2005 2006
Cardiff and Vale
4991 4686 –19
Cwm Taf
2590 2397 +2.7
Gwent Healthcare
2475 2176 –31
Hywel Dda
4455 4203 –37.9
North East Wales
3121 2875 –19.4
1343 1428 931 –30.6
Source: Western Mail
(a) In which of the NHS trusts has there been the greatest reduction in the number of
patients admitted to hospital with heart attacks? [1]
. . . .
(b) How have people’s attitudes to smoking changed over the last 15-20 years? [3]
. . . .
. . . .
. . . .
. . . .
(c) The reduction in the number of people admitted to hospital with heart disease may not be due only to smoking bans.
State two other lifestyle changes which could result in a decrease in the number of cases
of heart attack. [2]
. . . .
. . . .
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3. The following apparatus was set up to measure the energy content of a piece of food.
(a) State two measurements that you must take in order to find the energy content of the
food. [2]
. . . .
. . . .
(b) If you were comparing the energy content of two different foods state one other
measurement that must be taken. [1]
. . . .
Thermometer
Clamp Test-tube 20cm3water
Burning food Needle Wooden handle Heat resistant mat
Turn over.
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4. In 1971 the deer population of a remote island off the United States of America was 2000.
There was no predator of the deer on the island and fearing overgrazing the US Wildlife Service introduced 10 wolves onto the island.
The table below records the changes in population of the deer and wolves and the causes of death of the deer.
Year Wolf population Deer population Deer killed by predation
Deer dying of starvation
1971 10 2000 400 100
1972 12 2300 480 240
1973 16 2500 640 500
1974 22 2360 880 180
1975 28 2224 1120 26
1976 24 2094 960 2
1977 21 1968 840 0
1978 18 1916 720 0
1979 19 1952 760 0
1980 19 1972 760 0
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(a) Complete the plotting of the data for the wolf population on the grid below. Join the
plots with a ruler. [2]
Deer population/number
Year
Wolf population/number
(b) Describe the relationship between the population of deer and the population of wolves
between 1971 and 1980. [2]
. . . .
. . . .
. . . .
(c) The US Wildlife Service consider that the introduction of the wolves onto the island has, so far, been a success. What evidence is there in the data to support this? [2]
. . . .
. . . .
. . . .
. . . . 6
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5. (a) Explain the meaning of the term genetic modification (GM). [1]
. . . .
. . . .
(b) Give one example of a genetic modification that is carried out on a crop plant and state
the advantage of the modification. [2]
Example . . . .
Advantage . . . . . . . .
(c) Suggest one scientific reason why some people are concerned about the genetic
modification of plants and animals. [1]
. . . .
. . . .
4
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6. 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) Which three foxes listed would you expect to have the most similar DNA? [1]
. . . .
(b) Underline the name of the classification group you used to answer (a). [1]
Class Order Genus Species
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7. In 1960, a population of wild rats in Wales was found to be resistant to the concentrations of Warfarin that normally killed them. Scientists investigated the effect of Warfarin on resistant and non-resistant rats.
They used samples of the population which showed resistance in the wild and equal numbers of laboratory-bred non-resistant rats. They noted the percentage that survived various concentrations of Warfarin. The results are shown in the graph.
Rats surviving/%
Concentration of Warfarin/arbitrary units
(a) (i) Compare the effect of increasing the concentration of Warfarin on resistant and
non-resistant rats. [2]
. . . .
. . . .
. . . .
(ii) State the percentage deaths of resistant and non-resistant rats at a Warfarin
concentration of 10 arbitrary units. [1]
I. Resistant . . . .
II. Non-resistant . . . .
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9 (b) Explain how resistance to Warfarin has evolved and spread in populations of rats since
1960. [4]
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
(c) (i) State one scientific reason in favour of using laboratory rats for this investigation.
[1]
. . . .
. . . .
. . . .
(ii) State one reason why animal rights supporters might not be in favour of using
them. [1]
. . . .
. . . .
. . . .
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8. (a) Underline one of the following stimuli which is not involved in a withdrawal reflex. [1]
Temperature Light
Electrical
(b) Name the type of cell which responds to stimuli. [1]
. . . .
(c) In a withdrawal reflex,
(i) in which part of the central nervous system is a connecting nerve cell found; [1]
. . . .
(ii) what is the function of a connecting nerve cell; [1]
. . . .
. . . .
(iii) what type of effector is involved? [1]
. . . .
5
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9. The diagram below shows the evolutionary links between some animals.
Human Chimpanzee
Gorilla
Orang-utan
Monkeys
Mice 6 million years ago
EVOLUTION
130 million years ago
(Modified from Nature 2008 Vol 418)
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From the diagram, underline the correct answer to parts (a) and (b). [2]
(a) (i) Chimpanzees are most closely related to orang-utans.
(ii) Chimpanzees are most closely related to humans.
(iii) Gorillas are most closely related to monkeys.
(iv) Mice and humans do not have a common ancestor.
(b) (i) Humans evolved from monkeys.
(ii) Humans evolved from chimpanzees.
(iii) Chimpanzees evolved from monkeys.
(iv) Humans and monkeys had a common ancestor.
(c) During evolution of the animals shown in the diagram, a sudden change took place in the structure of a protein molecule.
(i) What chemical controls the production of protein molecules? [1]
. . . .
(ii) What name is given to the sudden change in this chemical? [1]
. . . .
(Questions continue overleaf)
(235-02) 5 10. (a) Describe how you would test a sample of urine for glucose. Give details of any
necessary measurements in the procedure. [2]
. . . .
. . . .
. . . .
. . . .
(b) What would you expect to observe as a result of testing urine from [2]
(i) a diabetic person;
. . . .
(ii) a healthy person who is not a diabetic?
. . . .
(c) Name the hormone that controls the levels of blood glucose. [1]
. . . .
