GCSE 239/02
ADDITIONAL SCIENCE
HIGHER TIER BIOLOGY 2
P.M. WEDNESDAY, 20 May 2009 45 minutes
VP*(S09-239-02)
ADDITIONAL MATERIALS
In addition to this paper you may require a calculator.
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.
For Examiner’s use only
3 4
1 7
2 4
5 3
4 7
7 6
6 8
9 7
Total 50
8 4
Question Maximum Mark
Mark Awarded
Answer all questions 1. The diagram shows the human digestive system.
(a) Label A–C on the diagram. [3]
A
B
C
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Turn over.
(239-02)
7 (b) A piece of visking tubing was knotted at the lower end and then filled with a starch solution
and enzyme mixture. The top of the tube was then knotted around a cocktail stick and placed in a test tube of water at 35°C. The apparatus is shown below.
After one hour the water in the test tube was tested for the presence of both starch and sugar.
The results are shown below.
Starch Sugar
no no
no yes At start of experiment After one hour
Water in test tube
(i) Explain why there was sugar but no starch in the water in the test tube after one hour.
[3]
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(ii) Name the enzyme used in this experiment. [1]
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cocktail stick
test tube
starch solution and enzyme mixture
visking tubing
water at 35°C
2. In 2005 – 2007 an European Union/Welsh Assembly Government project was set up to buy 24 000 female lobsters from fishermen. The captured female lobsters had a V-shaped notch cut in their tails before being released back into the sea.
The project is managed by the South Wales Sea Fisheries Committee.
The following is part of a notice displayed on notice boards in fishing villages and ports in South Wales.
South Wales Sea Fisheries Committee
Lobster
The minimum size of lobsters which may be taken from the sea in this district is 90 millimetres carapace measurement. This is the distance from the back of the eye socket to the rear edge of the carapace.
Lobsters with a ‘V’ notched tail are protected by law and must be returned to the sea.
carapace
V notch
(239-02) Turn over. 4 The following table provides some information about the growth and egg production of female lobsters:
Carapace length of female lobster /mm
Number of eggs produced each year
90 7000
150 20 000
(a) State the relationship between female lobster size and egg production. [1]
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(b) Suggest why all V-notched lobsters, which are protected by law, must be returned to the sea.
[2]
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(c) The protection of lobsters helps to maintain the biodiversity of the seas around South Wales.
What is meant by the term biodiversity? [1]
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3. The figure below shows the world population between 1950 and 2050 (estimated).
An effect of the increase in world population will be an increase in the percentage of the population living in urban areas (towns and cities) and a decrease in the percentage living in rural (farming) areas.
(a) (i) Suggest why an increase in the number of people living in urban areas will result in a decrease in the agricultural land available for growing crops. [1]
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(ii) State one effect of the decrease in argricultural land on humans. [1]
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0 2 6 8
4
2008 2050
1950 10
Key:
Urban Rural World
population /billions
Date
(239-02) Turn over. 4 (b) One of the systems that scientists are studying to solve the problem of argricultural land
shortage is Vertical Farming. Crops would be grown indoors in specially designed “living towers” (high rise tower blocks) in the centre of urban areas. This has been tried out in Chicago.
The table below shows some data about the delivery of tomatoes to the people of Chicago in one year.
Mass of tomatoes delivered in one year
Existing farm land Vertical farming
Land needed to grow tomatoes 1 150 acres 7 acres
Miles travelled in bringing tomatoes
into Chicago 959 300 0
Fuel consumed in bringing tomatoes
into Chicago 39 000 000 litres 0
15 914 tonnes
State two environmental advantages of growing tomatoes in Vertical Farming systems. [2]
(i) . . . .
(ii) . . . .
4. Sarah and Bethan set up the apparatus shown below on a laboratory bench near a window. The apparatus was left for 48 hours so that the green pond weed could acclimatise to the conditions.
After 48 hours they measured the percentage of carbon dioxide and oxygen dissolved in the water over the next 24 hour period.
window
beaker water
green pond weed
The readings taken by Sarah and Bethan are shown in the table below.
Dissolved gases / %
Time oxygen carbon dioxide
12.00 midnight 60 29
4.00 am 45 51
8.00 am 17 68
12.00 noon 47 44
4.00 pm 59 19
8.00 pm 69 26
12.00 midnight 61 29
(239-02)
Turn over. 7 (a) (i) Plot the data for oxygen on the grid below and join the plots with a ruler.
The data for carbon dioxide has been plotted for you. [3]
0 20 60 80
12.00 midnight
40
4.00 am
8.00 am
12.00 noon
4.00 pm
8.00 pm
12.00 midnight
carbon dioxide
Dissolved gases / %
Time
(ii) At which times is the percentage of carbon dioxide equal to the percentage of oxygen?
[1]
. . . .
(b) Explain why the percentage of oxygen increases and the percentage of carbon dioxide
decreases after 8 am. [3]
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3 5. Stem cells are present in a child’s baby teeth. It is now possible to store stem cells.
When a baby tooth falls out, it is sealed in a container of milk and sent to a laboratory where the stem cells are allowed to multiply until they reach approximately one million cells. These cells are then stored in liquid nitrogen at –190°C.
(a) What is a stem cell? [1]
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(b) State one advantage to a person of storing their own stem cells. [1]
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(c) In a plant, what name is given to the area of growth where stem cells are found? [1]
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6. The data shown in the diagram shows the biomass of organisms and the mass of insecticide found in organisms living in or near a lake.
The areas of the rectangles (drawn to scale) represent the total mass of the organisms. The number of dots in each rectangle indicates the mass of insecticide found in the organisms.
water plants herbivorous fish
large carnivorous fish carnivorous birds
(239-02) Turn over.
(a) Name the organisms in the diagram in which
(i) the mass of insecticide is greatest; [1]
. . . .
(ii) the concentration of insecticide per unit mass is greatest. [1]
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(b) Use the diagram to estimate the mass of carnivorous fish that could be supported by 1000 kg
of herbivorous fish. [1]
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(c) Name the two types of food pyramids which could be constructed for a habitat [2]
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(d) (i) Describe two possible environmental disadvantages of the continuous use of an
insecticide near the lake. [2]
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(ii) State one method of controlling insect pests other than by the use of insecticides.
[1]
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8
7. The following is a summary of an article from New Scientist (December 2006).
Throughout the world, there are over 200 “dead zones” which occur in coastal waters and estuaries. In these areas, only the most primitive forms of life, such as bacteria, can exist. In order to improve this situation, there would need to be a reduction in the use of fertiliser on farms and an improvement in sewage treatment.
(a) Explain how the fertiliser, used on farms, can cause “dead zones”. [5]
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(b) Suggest one reason why improving sewage treatment might be unpopular with politicians
and industry. [1]
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Turn over.
(239-02)
8. The graph shows the rate at which a plant takes in a mineral through its roots.
4
00 10
chemical X added
5 Rate of
uptake of mineral
/ a.u.
Time/minutes
After 5 minutes a chemical, X, was added to the roots of the plant. This stopped respiration in the root cells.
(a) State how the graph tells you that the mineral is being taken into the roots by active
transport. [1]
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(b) Name two substances that are needed for active transport to take place. [2]
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(c) State one advantage of active transport. [1]
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(Questions continue over the page)
9. The first contact lenses to be developed were made of glass. The diagram shows what happened when a glass contact lens was put on the eye.
3
2 1
Front surface of eye (Cornea)
eye fluid
Lactic acid
Cells of the cornea produce lactic acid which causes water to enter by osmosis Air
layer of tears
Increased pressure causes pain
Glass contact lens The glass stops oxygen from reaching the cornea
area enlarged
These lenses proved to be unsuitable because they caused pain.
(a) The diagram shows water entering the cornea of the eye by osmosis.
Define osmosis. [2]
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. . . .
(b) At point 2 in the diagram, lactic acid is produced. Name the process which produces lactic
acid. [1]
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(c) Modern contact lenses are gas permeable.
Use the information in the diagram, to explain why these modern contact lenses are more
suitable than glass contact lenses. [4]
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Water
