1. Coral reefs are formed and maintained by very large numbers of simple animals called polyps. These polyps have single-celled algae (simple photosynthetic organisms) living inside their cells.

It is thought that when the sea is too warm the relationship between the coral polyps and the algae breaks down, and the reef begins to look white (becomes bleached). If the sea temperature falls again within a few weeks then the coral polyps and the algae reunite. If it does not, then the coral polyps die.

In 1998, 16% of the worlds coral reefs showed some bleaching. Half of these damaged reefs are now recovering.

The Great Barrier Reef off the east coast of Australia has been badly bleached in the last few years. The average sea temperature on the reef has increased by 0.3 C in the last century. It is feared that southern and central sections of the Great Barrier Reef are likely to be severely affected by sea temperature rises in the next 20-40 years.

(a) Name a method by which global sea temperatures can be monitored.

.....................................................................................................................................

(1)

(b) Suggest how the algae normally help the coral polyps to survive.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(c) Some recovery in the Great Barrier Reef may be taking place at present. Suggest a possible explanation for this, other than change in sea temperature.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)(Total 5 marks)

2. There is widespread concern about the possible effects of human activities on global warming.

(a) State two sources of evidence that global warming has been increasing over the past 150 years.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(b) Dinosaurs became extinct about 65 million years ago, possibly because of climate change resulting from the impact of a meteorite with the Earth.

(i) Suggest how this impact might have caused the extinction of the dinosaurs.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(3)

(ii) Give one alternative explanation that has been proposed by reputable biologists to explain the mass extinction of the dinosaurs.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(2)

(c) Climate change could mean extinction for many of Britains rare species of plants and animals.

Suggest how rare species which do not become extinct may be affected by global warming.

.....................................................................................................................................

.....................................................................................................................................

(1)

(d) Recent global warming might be the result of an increase in greenhouse gases in the atmosphere, related to the burning of fossil fuels by human activity since the Industrial Revolution.

(i) Name two greenhouse gases other than carbon dioxide.

1 ........................................................................................................................

2 ........................................................................................................................

(2)

(ii) Give one explanation for recent global warming other than burning fossil fuel.

...........................................................................................................................

...........................................................................................................................

(1)(Total 11 marks)

3. The photograph below shows brine shrimps.

A student carried out an investigation to determine the effect of temperature on the hatching success of brine shrimp eggs. The results are shown below.

Temperature/ C 22 24 26 28 30 32

% Eggs hatching 36 40 42 44 42 41

(a) Describe the pattern shown by the data in this table.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(b) Suggest why brine shrimps are affected by temperature in the way shown by the data.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(c) Suggest how global warming, directly or indirectly, might alter brine shrimp populations.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(3)(Total 7 marks)

4. Changes in the global environment are investigated using remote sensing techniques.

(a) Describe and explain what is meant by remote sensing.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(3)

(b) Describe two kinds of data commonly collected by remote sensing which can be used by scientists studying climate change and its effects.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(c) Techniques such as remote sensing have been available only in recent times.Information from dendochronology is usually limited to the past 1000 years.

Apart from dendochronology, explain how scientists can investigate ecological changes over the past 12 000 years.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(4)(Total 9 marks)

5. The diagram below shows a mayfly nymph, an invertebrate which lives in freshwater streams.

(a) Give two features, visible in the diagram, which show how mayfly nymphs are adapted for living in an aquatic habitat. In each case, explain how the feature helps the mayfly nymphs to live in water.

1 ..................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

2 ..................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(4)

(b) Freshwater streams may be polluted with organic effluents. One of the effects of an organic effluent is to reduce the concentration of dissolved oxygen in thewater. The graph below shows the distribution of larvae of Chironomus, a freshwater invertebrate, at increasing distances downstream from the source ofan organic effluent.

N u m b e r s o f

l a r v a eC h i r o n o m u s

D i s t a n c e d o w n s t r e a m f r o m e f f l u e n t

P o i n t a t w h i c h e f f l u e n te n t e r s t h e s t r e a m

(i) Suggest and explain two ways in which Chironomus larvae could be adapted to living in water with a low concentration of dissolved oxygen.

1 ........................................................................................................................

...........................................................................................................................

...........................................................................................................................

2 ........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(4)

(ii) Immediately after the point at which the effluent enters the stream, numbers of Chironomus larvae decrease and then increase.

Suggest an explanation for this increase in the numbers of Chironomus larvae.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(2)(Total 10 marks)

6. Oil is a fossil fuel. It can be used as fuel in power stations and in engines. Figure 1

below shows oil production between 1960 and 2004.

When oil is burnt, some gases, including carbon dioxide, are released. Some processes by which carbon dioxide is added to, or removed from, the atmosphere areshown in Figure 2.

Carbon dioxide is a greenhouse gas, which has an influence upon the mean global temperature of the Earths surface. Changes in this temperature between 1960 and 2004 are shown in Figure 3.

Figure 1. Oil production in thousands of barrels per day between 1960 and 2004

8 0 0 0 0

7 0 0 0 0

6 0 0 0 0

5 0 0 0 0

4 0 0 0 0

3 0 0 0 0

2 0 0 0 0

1 0 0 0 0

0

1964

1960

1962

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

Y e a r

9 0 0 0 0

Oil

prod

uctio

n/ 1

000

barr

els p

er d

ay

Figure 2. Diagram showing part of the carbon cycle

C a r b o n d i o x i d e i n t h e a t m o s p h e r e

F u e l i n a p o w e r s t a t i o n

P r o c e s s B

P r o c e s s A

P r o c e s s C

P r o c e s s C

O i lP l a n t b i o m a s s

D e c a y i n g m a t e r i a l

Figure 3. Changes in the mean global temperature of the Earths surface between 1960 and 2004

1964

1960

1962

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

Y e a r

1 4 . 8

1 4 . 6

1 4 . 4

1 4 . 2

1 4 . 0

1 3 . 8

1 3 . 6

1 3 . 4

1 3 . 2

1 3 . 0

Tem

pera

ture

/ C

(a) Name the processes A, B and C shown in Figure 2.

A .................................................................

B .................................................................

C .................................................................(3)

(b) Describe the changes in the production of oil between 1960 and 2004 as shown in Figure 1.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(3)

(c) Study the graphs in Figures 1 and 3. Do the graphs support the theory that the rise in oil production is linked to the rise in global temperature? Give reasons for your answer.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

..............................................................................................................................

.......(2)

(d) Carbon dioxide is a greenhouse gas. Explain the term greenhouse gas and give an example of another greenhouse gas.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(e) Oil is one type of fossil fuel. Give one other example of a fossil fuel.

.....................................................................................................................................

(1)

(f) Energy crops are plants grown in large plantations to provide a sustainable source of energy. These energy crops, such as fast-growing willow, are likely to become far more common in the future. Explain the term sustainable.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(g) There is some concern that the replacement of traditional crops, such as wheat, by energy crops could affect the distribution of some birds normally found on farmland.

A study was undertaken to investigate the effect of changing land use on the distribution of bird species. Bird surveys were carried out in four habitats: arable land, grassland, willow plantation on former arable land and willow plantation on former grassland. The numbers of lapwing, snipe and woodcock were recorded by walking through each survey area for one hour three times during one summer. The results of this study are shown in Figure 4.

Figure 4. Results of the bird surveys that were carried out on arable land and grassland and in willow plantations growing on former arable and grassland

l a p w i n gs n i p ew o o d c o c k

1 . 0

0 . 9

0 . 8

0 . 7

0 . 6

0 . 5

0 . 4

0 . 3

0 . 2

0 . 1

0Mea

n nu

mbe

r of b

irds

reco

rded

per

site

pe

r vis

it

A r a b l e l a n d

W i l l o w o n

g r a s s l a n d

G r a s s l a n dW i l l o w o n a r a b l e

l a n d

Use the data in Figure 4 to describe the effect of planting willow on the distribution of these three species of bird.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(3)(Total 16 marks)