Download looking back

CHAPTER 8: The dynamic Earth
LOOKING BACK
1. Which layers of the Earth have the following characteristics?
1. Completely molten
2. Partially molten
3. Includes solid rock, soil and landforms
4. Solid and mostly made up of iron
5. Lies above the surface
2. Describe two pieces of evidence that supported Wegener's theory of continental drift.
3. Explain how scientists know about what lies deep below the surface of the Earth
without going there.
4. According to the theory of plate tectonics, the Earth's crust is divided into a number of
slowly moving plates.
1. What makes the plates move?
2. What can happen when two plates slide past each other?
3. How does the plate tectonics theory explain the increasing height of the
Himalayas?
5. What is the major difference between the continental drift theory and the theory of
plate tectonics in terms of what makes up the Earth's crust?
6. Where on Earth is the Ring of Fire and why does it exist?
7. How is an ocean ridge different from a subduction zone?
8. When oceanic crust pushes against continental crust, why does the oceanic crust slide
underneath the continental crust?
9. Describe the movements in the Earth's crust that cause the folding of rock that has
shaped most of the Earth's mountains.
10. Explain how faults are created.
11. Copy the diagrams below and label them using the following words: anticline,
continental crust, magma, normal fault, oceanic crust, reverse fault, solid upper
mantle, syncline.
(a) A subduction zone
(b) Two types of faulting
(c) Folding upwards and downwards
12. The San Andreas Fault makes much of coastal California, including the cities of Los
Angeles and San Francisco, susceptible to earthquakes.
1. Explain why the San Andreas Fault is called a slip fault.
2. What causes major earthquakes along this fault?
13. Distinguish between the epicentre of an earthquake and its focus.
14. What is a seismograph used to measure?
15. How much more energy is released by an earthquake that registers 6.0 on the Richter
scale than by one that registers 7.0 on the Richter scale?
16. Suggest two reasons why an earthquake that registers 6.6 on the Richter scale can
cause more deaths and devastation than an earthquake that registers 7.9 on the Richter
scale.
17. Before a volcano erupts, its vents are blocked with thick, pasty lava.
1. What change takes place to cause the volcano to erupt?
2. How is the lava emerging from a volcano different from magma?
18. Name three gases present in the lava that are released from a volcano.
19. Distinguish between a dormant volcano and an extinct volcano.
20. Identify two causes of tsunami.
Continental drift
Two hundred million years ago
1. The map below shows the continents as they were 200 million years ago.
(a) Identify the name of the supercontinent that existed 225 million years ago before it broke
up into Laurasia and Gondwana. ..............................................................................................
(b) Identify the name of the continents of today
that are labelled with the letters A–E.
A: ..................................................................
B: ..................................................................
C: ..................................................................
D: ..................................................................
E: ..................................................................
(c) Fossils of a fern called Glossopteris have been found in the locations marked on the map
below.
Explain how scientists use this
information to support the theory
of continental drift.
................................................................
................................................................
................................................................
................................................................
................................................................
................................................................
................................................................
Alfred Wegener
2. During the late 1800s and early 1900s, scientists collected evidence that indicated that the
continents were moving. In 1912, Alfred Wegener made a number of observations about
continental drift.
(a) Explain what Wegener noticed about the shapes of coastlines of various continents such
as Africa and South America.
..................................................................................................................................................
(b) Explain how fossils and rock types supported Wegener’s theory.
..................................................................................................................................................
..................................................................................................................................................
Plate tectonics
Movement in the South Atlantic
1. The following diagram shows the ocean floor of the South Atlantic Ocean.
(a)
(b)
(c)
(d)
Identify the feature labelled A. ................................................................................................
Identify the material rising up to the surface at B. ..................................................................
On the diagram draw in the convection currents in the upper mantle (asthenosphere).
Explain why the South American plate and the African plate are moving apart.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
North of Australia
2. The following map shows the Australian–Indian plate, and other plates to the north. The
arrows show the direction of plate movement.
(a) Name plates X and Y.
X: ..........................................................................
Y: ..........................................................................
(b) Name the type of plate interaction at location ‘A’.
..............................................................................
(c) Name the geological feature resulting from the
plate interaction at A.
...............................................................................
Folding and faulting
The San Andreas Fault
1. The following diagram and photograph shows the San Andreas Fault in California.
(a) Identify this type of fault.
....................................................................................................
(b) On the diagram above use arrows to show the
direction of the plate movement on either side
of the fault line.
(c) What is produced when movement occurs along
this fault line?
………………………………………….……....
CHAPTER 8: The dynamic Earth
Worksheet 8.3
Page 2
Bending rocks
2. When rocks are squeezed deep in the Earth they may soften and bend rather than break.
Look at the supplied diagram below.
(a) Identify the folds labelled X and Y.
X: ...............................................................................
Y: ...............................................................................
(b) The photo shows a section of
rocks in the Hamersley range
in Western Australia. Explain
how these formations were
produced.
......................................................
......................................................
......................................................
......................................................
......................................................
......................................................
......................................................
Normal and reverse faults
3. Draw and label 2D diagrams to distinguish between a normal and a reverse fault. Show the
direction of rock movement along each fault.
Normal fault
Reverse fault
Earthquakes
1. The following diagram shows a section of the Earth’s crust where an earthquake is being
generated.
(a) Identify the points labelled A and B:
A: .............................................................................................................................................
B: .............................................................................................................................................
(b) Identify the likely cause of the earthquake illustrated.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
(c) Australia does not experience many earthquakes. Explain.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
CHAPTER 8: The dynamic Earth
Worksheet 8.4
Page 2
2. The following table provides information about earthquake intensities. The description
information is jumbled. Use the letters G–L to match the Richter magnitude and the
description of effects.
Richter
magnitude
Description of effects
(A) 1.0
(G) Causes serious damage over very large areas
(B) <3.5
(H) Can be destructive over a 100 km wide area
(C) <6.0
(I) Generally noticeable by humans
(D) 6.1–6.9
(J) Can cause serious damage in areas several hundreds of km across
(E) 7.0–7.9
(K) Undetectable by humans
(F) ≥8
(L) Slight damage to well-designed buildings but can cause large cracks and
material failure to poorly constructed buildings
A: ………………………….. B: ………………………….. C: …………………………..
D: ………………………….. E: ………………………….. F: …………………………...
3. The following diagram shows how a tsunami forms.
Explain why the height of the wave increases as it approaches the land.
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
Plotting earthquake
activity
Student: ................................................................................................................. Class: ..........................................
The following table contains data for large earthquakes that have occurred in the Pacific Rim in
the
last 100 years.
Magnitude
Location
Latitude
Longitude
A
8.5
Kuril islands
45°N
150°E
B
8.5
Argentina
29°S
71°W
C
8.5
Banda Sea
5°S
132°E
D
8.6
Tibet
29°N
96°E
E
8.6
Indonesia
2°N
97°E
F
8.8
Ecuador (off
coast)
1°N
82°W
G
9.0
Kamchatka
53°N
160°E
H
9.1
Sumatra
3°N
96°E
I
9.2
Alaska
61°N
148°W
J
9.5
Chile
38°S
73°W
1. Plot the location of each earthquake on the map below.
CHAPTER 8: The dynamic Earth
Worksheet 8.5
Page 2
2. Account for the location of these earthquakes in relation to the tectonic plates.
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
3. The Chilean earthquake occurred in 1960. What effect does an earthquake of this magnitude
have on the ground surface?
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
Volcanic activity
Student: ................................................................................................................. Class: ..........................................
Steep-sided volcanoes
1. The diagram shows a steep-sided volcano forming as a result of tectonic activity.
(a) Identify the type of plate boundary that
leads to the formation of the volcano.
.......................................................................................
(b) Explain why the oceanic crust melts to
form magma.
.......................................................................................
(c) Identify a location in the southern
hemisphere where such an event occurs.
.......................................................................................
Eruption
2. The following events describe the eruption of a steep-sided volcano. The events are jumbled.
Rearrange the letters A–F to arrange the events in the correct sequence.
A. Magma rises towards the surface.
B. Lava is blasted into the air.
C. The expanding gases cause an explosion that rips open the vent.
D. Ash, cinders and dust rain down onto the ground.
E. Low-density magma rises under pressure into the magma chamber.
F. Dissolved gases expand as the magma rises.
Answer: ...........................................................................................................................................
Our volcanic neighbours
3. The diagram below shows the
region north and east of Australia.
Volcanoes are marked on the map.
(a) Explain why the volcanoes are located in these places.
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
(b) Explain why there are no active volcanoes in
Australia.
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
...........................................................................................
Investigating the dynamic Earth
1.
(a) Identify each of the layers of the Earth shown in the diagram below.
(b) In which of these layers does convection occur? ..............................................................
(c) Which of these layers is solid? ..........................................................................................
2.
(a) Explain what is meant by the term tectonic plate.
.........................................................................................................................................................
...............................................................................................................................
(b) Complete the table below by describing the different forms of plate motion and giving one
example of where each can be seen occurring.
Plate motion
Spreading
Sliding (translation)
Subducting
Description
Example
(c) The simplified map below shows the movement of the main plates that form the crust.
On the map, mark:
(i) the Ring of Fire
(ii) a converging plate boundary
(iii) where you would find a mid-ocean ridge.
3.
(a) Explain, with the aid of diagrams, how mountains can be formed by:
(i) folding
(ii) faulting.
(b) Describe the difference between a slip fault and a normal fault.
.......................................................................................................................................................
.......................................................................................................................................................
.............................................................................................................
4. Consider the following information on seismic waves.
There are three main types of wave that are generated by earthquakes: P-waves, S-waves and L-waves.
These waves differ in terms of their orientation, their speed and the regions of the Earth through which they
travel.
P-waves are the fastest of the waves and so are the first to be detected by a seismometer. As a result, they
were named primary waves (abbreviated to P-waves). Their speed depends on which part of the Earth they
are travelling through. In the crust, P-waves have a speed of 5 km/s, in the top of the mantle they travel at
about 8 km/s and at 14 km/s in the bottom of the mantle.
The second set of waves to be detected are the secondary or S-waves, which travel at about 60% of the
speed of P-waves. The S-waves can only travel through the crust and mantle, and will actually bounce off
the boundary between the core and the mantle. As P-waves and S-waves are both able to travel through the
interior of the Earth, they are said to be body waves.
L-waves are only able to travel on the surface of the Earth, so they are classed as surface waves. They
travel much more slowly than either the P-waves or S-waves and so are the last to arrive at a seismograph.
However, these surface waves are responsible for the majority of an earthquake’s destructive power, as all
of the L-wave energy is distributed across the surface of the Earth rather than being dissipated in the
Earth’s interior as in P- and S-waves.
(a) Below is a seismogram, which is formed by a strip of paper moving past a stationary pen.
On the seismogram identify the P-, S- and L-waves. Use the information you have just read to
justify your answer.
.......................................................................................................................................................
.......................................................................................................................................................
.............................................................................................................
(b) Which seismic waves travel the fastest? .........................................................................
(c) Which seismic waves are able to travel through:
(i) the crust
...................................................................................................................................
(ii) the core?
...................................................................................................................................
(d) The magnitude of an earthquake on the Richter scale is calculated from the amplitude of the
strongest wave reaching the seismograph during an earthquake. Which seismic wave would
be analysed to produce the magnitude? ......................................................
5. Explain why earthquakes that have their epicentre in the ocean cause tsunamis, while those with
an epicentre far inland do not.
.............................................................................................................................................................
.............................................................................................................................................................
.............................................................................................................................................................
.........................................................................................................
Continental drift
Answers
Two hundred million years ago
1. The map below shows the continents as they were 200 million years ago.
(a) Identify the name of the supercontinent that existed 225 million years ago before it broke
Pangaea
up into Laurasia and Gondwana. ..............................................................................................
(b) Identify the name of the continents of today
that are labelled with the letters A–E.
Asia
A: ..................................................................
Australia
B: ..................................................................
Antarctica
C: ..................................................................
Africa
D: ..................................................................
North America
E: ...................................................................
© MAPgraphics Pty Ltd, Brisbane
(c) Fossils of a fern called Glossopteris have been found in the locations marked on the map
below.
Explain how scientists use this
information to support the theory of
continental drift.
These
continents were all once part
................................................................
of
Gondwana, therefore the spores
................................................................
of
the fern could be transported
................................................................
across
the land in wind currents to
................................................................
colonise
new areas. As Gondwana
................................................................
broke
up and oceans separated the
................................................................
ferns,
this process could no longer
................................................................
occur.
................................................................
Alfred Wegener
2. During the late 1800s and early 1900s, scientists collected evidence that indicated that the
continents were moving. In 1912, Alfred Wegener made a number of observations about
continental drift.
(a) Explain what Wegener noticed about the shapes of coastlines of various continents such
as Africa and South America.
The
east coast of South America and the west coast of Africa fit together like a jigsaw. This
..................................................................................................................................................
suggests
that these two continents were once joined and then split apart as continental drift
..................................................................................................................................................
occurred.
..................................................................................................................................................
(b) Explain how fossils and rock types supported Wegener’s theory.
The occurrence of similar fossils and rock types on the margins of continents such as Africa
..................................................................................................................................................
and South America supported the theory that these continents were once joined.
..................................................................................................................................................
Plate tectonics
Answers
Movement in the South Atlantic
1. The following diagram shows the ocean floor of the South Atlantic Ocean.
Mid-ocean ridge (Mid-Atlantic ridge)
(a) Identify the feature labelled A. ................................................................................................
Magma
(b) Identify the material rising up to the surface at B. ..................................................................
(c) On the diagram draw in the convection currents in the upper mantle (asthenosphere).
Convection
currents
..................................................................................................................................................
(d) Explain why the South American plate and the African plate are moving apart.
The rising magma causes the sea floor spreading. Forces from the rising magma push the
..................................................................................................................................................
plates apart.
..................................................................................................................................................
..................................................................................................................................................
CHAPTER 8: The dynamic Earth
Worksheet 8.2
Page 2
North of Australia
2. The following map shows the Australian–Indian plate, and other plates to the north. The
arrows show the direction of plate movement.
(a) Name plates X and Y.
Eurasian plate
X: ..........................................................................
Pacific plate
Y: ..........................................................................
(b) Name the type of plate interaction at location ‘A’.
Converging plates — collision zone
..............................................................................
(c) Name the geological feature resulting from the
plate interaction at A.
Mountains (Himalayas)
...............................................................................
© MAPgraphics Pty Ltd, Brisbane
Folding and faulting
Answers
The San Andreas Fault
1. The following diagram and photograph shows the San Andreas Fault in California.
(a) Identify this type of fault.
Slip
fault (or strike-slip fault or transform fault)
....................................................................................................
(b) On the diagram above use arrows to show the
direction of the plate movement on either side
of the fault line.
(c) What is produced when movement occurs along
this fault line?
Earthquakes
………………………………………….……....
© Austral International/Rex Features
CHAPTER 8: The dynamic Earth
Worksheet 8.3
Page 2
Bending rocks
2. When rocks are squeezed deep in the Earth they may soften and bend rather than break.
Look at the supplied diagram below.
(a) Identify the folds labelled X and Y.
X: Syncline
...............................................................................
Anticline
Y: ...............................................................................
(b) The photo shows a section of
rocks in the Hamersley range
in Western Australia. Explain
how these formations were
produced.
Compression forces deep in
......................................................
the Earth squeezed and
......................................................
folded these rocks to form
......................................................
folds.
......................................................
......................................................
......................................................
......................................................
© ANT Photo Library/D. & T. O'Byrne
Normal and reverse faults
3. Draw and label 2D diagrams to distinguish between a normal and a reverse fault. Show the
direction of rock movement along each fault.
Normal fault
Reverse fault
Earthquakes
Answers
1. The following diagram shows a section of the Earth’s crust where an earthquake is being
generated.
(a) Identify the points labelled A and B:
Epicentre
A: .............................................................................................................................................
Focus
B: .............................................................................................................................................
(b) Identify the likely cause of the earthquake illustrated.
Sideways movement along a slip-strike (transform) fault at the plate boundary
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
(c) Australia does not experience many earthquakes. Explain.
The
Australian continent is not near a plate boundary or hot spot, so earthquakes do not
..................................................................................................................................................
occur
often.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
CHAPTER 8: The dynamic Earth
Worksheet 8.4
Page 2
2. The following table provides information about earthquake intensities. The description
information is jumbled. Use the letters G–L to match the Richter magnitude and the
description of effects.
Richter
magnitude
Description of effects
(A) 1.0
(G) Causes serious damage over very large areas
(B) <3.5
(H) Can be destructive over a 100 km wide area
(C) <6.0
(I) Generally noticeable by humans
(D) 6.1–6.9
(J) Can cause serious damage in areas several hundreds of km across
(E) 7.0–7.9
(K) Undetectable by humans
(F) ≥8
(L) Slight damage to well-designed buildings but can cause large cracks and
material failure to poorly constructed buildings
I
K
L
A: …………………………..
B: …………………………..
C: …………………………..
J
H
G
D: …………………………..
E: …………………………..
F: …………………………...
3. The following diagram shows how a tsunami forms.
Explain why the height of the wave increases as it approaches the land.
The
waves move fast in deep water and slow down in shallow water. The wave crests begin
.........................................................................................................................................................
to
bunch up in the shallow water as they slow down, eventually merging to produce
.........................................................................................................................................................
extremely
high waves.
.........................................................................................................................................................
.........................................................................................................................................................
Plotting earthquake
activity
Answers
The following table contains data for large earthquakes that have occurred in the Pacific Rim in
the
last 100 years.
Magnitude
Location
Latitude
Longitude
A
8.5
Kuril islands
45°N
150°E
B
8.5
Argentina
29°S
71°W
C
8.5
Banda Sea
5°S
132°E
D
8.6
Tibet
29°N
96°E
E
8.6
Indonesia
2°N
97°E
F
8.8
Ecuador (off
coast)
1°N
82°W
G
9.0
Kamchatka
53°N
160°E
H
9.1
Sumatra
3°N
96°E
I
9.2
Alaska
61°N
148°W
J
9.5
Chile
38°S
73°W
1. Plot the location of each earthquake on the map below.
© MAPgraphics, Pty Ltd, Brisbane
CHAPTER 8: The dynamic Earth
Worksheet 8.5
Page 2
2. Account for the location of these earthquakes in relation to the tectonic plates.
Most
of these earthquakes are along the Pacific Rim except for the Tibetan earthquake. The
.........................................................................................................................................................
border
of the Pacific represents the edges of the ocean plate and continental plates. These are
.........................................................................................................................................................
zones
of subduction, which lead to earthquakes and volcanic activity as the ocean plate is
.........................................................................................................................................................
pushed
below the continental plates. The Tibetan earthquake is the result of the Indo.........................................................................................................................................................
Australian
plate colliding with the Eurasian plate.
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
3. The Chilean earthquake occurred in 1960. What effect does an earthquake of this magnitude
have on the ground surface?
An
earthquake with a magnitude of 9.5 is catastrophic. The ground rises and falls during the
.........................................................................................................................................................
event,
resulting in complete devastation in the zone of the epicentre.
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
.........................................................................................................................................................
Volcanic activity
Answers
Steep-sided volcanoes
1. The diagram shows a steep-sided volcano forming as a result of tectonic activity.
(a) Identify the type of plate boundary that
leads to the formation of the volcano.
Subduction
zone
.......................................................................................
(b) Explain why the oceanic crust melts to
form magma.
Frictional heating
.......................................................................................
(c) Identify a location in the southern
hemisphere where such an event occurs.
West
coast of South America
.......................................................................................
Eruption
2. The following events describe the eruption of a steep-sided volcano. The events are jumbled.
Rearrange the letters A–F to arrange the events in the correct sequence.
A. Magma rises towards the surface.
B. Lava is blasted into the air.
C. The expanding gases cause an explosion that rips open the vent.
D. Ash, cinders and dust rain down onto the ground.
E. Low-density magma rises under pressure into the magma chamber.
F. Dissolved gases expand as the magma rises.
E, A, F, C, B, D
Answer: ...........................................................................................................................................
Our volcanic neighbours
3. The diagram below shows the
region north and east of Australia.
Volcanoes are marked on the map.
© MAPgraphics, Pty Ltd, Brisbane
(a) Explain why the volcanoes are located in these places.
The volcanoes are present along the boundaries of
...........................................................................................
plates. These plate boundaries are subduction zones.
............................................................................................
...........................................................................................
............................................................................................
(b) Explain why there are no active volcanoes in
Australia.
Australia does not lie near the edge of a plate (the
...........................................................................................
Indo-Australian plate). We have a small number of
............................................................................................
earthquakes. However, since the continent is a long
............................................................................................
way from a subduction zone or a slip-strike zone,
...........................................................................................
volcanoes do not form.
...........................................................................................
............................................................................................
............................................................................................
...........................................................................................
Answers
1.
(a)
(b) Mantle
(c) Crust and the inner core
2.
(a) Tectonic plates describe the moving interlocking pieces that make up the Earth’s lithosphere
(the crust and very top section of the mantle). These plates move on a layer of partially
molten rock in the upper mantle (asthenosphere).
(b)
Plate motion
Spreading
Description
Example
Plates are moving away from
Mid-Atlantic ridge (African
each other (diverging)
plate and North American
plate)
Sliding (translation)
Subducting
Plates are sliding laterally past
At San Andreas fault line
each other in different
(Pacific plate and North
directions
American plate)
The sliding of the edge of an
Marianas Trench (Pacific plate
oceanic plate under a
and Eurasian plate)
continental plate
(c) Answers to questions (i)–(iii are marked on the map below.
3.
(a)
(i) Large compressional forces beneath the Earth cause layers of rock to bend and crumple
without breaking. Most of the major mountain ranges around the Earth have been shaped
in this way.
(ii) Mountains can be formed by normal faults or reverse faults. They can also be formed by a
block sinking between others or by a block being pushed up by others.
(b) Slip (or transform) faults are those that occur where rocks move sideways past each other
along a fracture. When viewed from above, the rocks on either side of the crack will be
mismatched. Normal faults appear in rocks that have been stretched, causing the rocks on one
side of the fault to slip downwards. Large-scale normal faults create long cliff faces.
4.
(a)
The P-waves travel fastest so will reach the seismometer first; the L-waves will arrive last as
they are the slowest; S-waves arrive between P- and L-waves; the L-waves have the largest
amplitude.
(b) P-waves
(c)
(i) P- and S-waves through the crust; L-waves on the surface of the crust
(ii) P-waves
(d) L-waves
5. Tsunamis are caused when rock movement underwater displaces large volumes of water in the
ocean. As the energy of a seismic wave dissipates over distance, the closer the epicentre of the
earthquake is to water, and the more likely it is to cause rock movement and water displacement.
The dynamic Earth: Summary
Student: ................................................................................................................. Class: ..........................................
Use the listed words to complete the sentences.
collision
convection
denser
focus
fold
Gondwana
normal
Pangaea
ridges
volcanic
drift
lava
seismographs
dynamic
magnitude
subduction
fault
mantle
tectonics
1. The Earth is a …………….… system in which change is constantly occurring. The
movement of the continents and the growth of mountain ranges occur very slowly over
millions of years. However, the shock of an earthquake, volcanic eruption and even land
slips change the face of the Earth in a very short period of time.
2. Alfred Wegener proposed the theory of plate tectonics, in which he believed the continents
on the Earth were not fixed but were ‘floating’ on …………….… material in the upper
…………….…, and that these floating continents were constantly breaking apart from each
other and rejoining in new combinations in a process he called continental …………….…
3. In the distant past, all of the Earth’s continents were part of a single ‘super-continent’ that
was called …………….… Eventually this super continent broke up into a large northern
continent called Laurasia and a large southern continent called …………….…
4. The theory of plate …………….… explains continental drift. The crust of the Earth is
divided into large tectonic plates that move in response to …………….… currents in the
upper mantle. Collisions between plates are responsible for earthquakes and …………….…
action.
5. Plates can spread apart due to magma rising from the mantle. This occurs at mid-ocean
…………….…
6. Oceanic plates can collide with continental plates at …………….… zones. The oceanic plate
goes under the continental plate and this leads to mountain building, earthquakes and volcanic
activity.
7. Continents can collide at …………….… zones. In this case large mountains such as the
Himalayas are formed.
8. Plates may slide past each other and cause earthquakes. These …………….… lines are
called transform or slip-strike faults.
9. Rocks deep within the earth’s crust are heated and put under pressure. Under these
conditions the layers of rock can …………….… . Rock layers may also undergo faulting.
Faults can be classified as …………….… faults or reverse faults.
10. The movement of the crust can lead to an earthquake. This occurs at a point down, inside
the crust called the …………….… The point on the earth’s surface above the focus is the
epicentre and this is the site of greatest destruction. …………….… record the earthquake
waves. The Richter scale measures the …………….… of the earthquake.
11. Volcanoes are formed when magma rises from the mantle towards the surface.
…………….… is forced out of the ground and it may form a cone shaped volcano or lava
fields. The Pacific Rim is a major site of volcanic action due to the interaction of tectonic
plates.
NERVOUS SYSTEM














state the function of receptors and provide examples of at least three types
use a flowchart to show how receptors are involved in your ability to sense your
environment
use a flowchart to describe the stimulus–response model
describe how negative feedback can assist you in maintaining homeostasis
outline the overall function of the nervous system
outline the key components of the nervous system
draw a labelled diagram of the structure of a neuron
use a flowchart to show how a message is conducted and transmitted in the nervous
system
compare and contrast nervous impulses and neurotransmitters
use a flowchart to describe the process involved in a reflex action
explain the need for some reactions to be reflex actions
compare reflex actions with those under conscious control
describe how damage to the nervous system can result in paralysis
outline the effects of motor neuron disease on the ability to sense and respond to the
environment
ENDOCRINE SYSTEM



outline the overall function and key components of the endocrine system
recall the main glands of the endocrine system and some of the hormones they
produce
use a diagram to show how the stimulus–response model can be used to describe the
involvement of the endocrine system in homeostasis
CHAPTER 3: Control and coordination
The nervous and endocrine system
Sensory neuron
1. (a) State the function of a sensory neuron.
...................................................................................................................................................
...................................................................................................................................................
(b) Use words from the
list to label the
diagram of a sensory
neuron.
List: cell body;
axon; dendrite; axon
branches; nucleus
Sending an impulse
2. Complete the following flow chart about the transmission of messages in the nervous system
by inserting words from the list.
List: effector; interneuron; motor neuron; receptor; sensory neuron
Neurotransmitters
3. The following diagram shows the synapse between two neurons. The lists of statements about
the transmission of the nerve impulse across the synapse are jumbled. Use the code numbers
to place the statements in the correct order.
Jumbled statements:
1. Neurotransmitter chemicals are
released.
2. Neurotransmitters reach the dendrite.
3. An impulse travels along the axon.
4. Neurotransmitters cross the synapse.
5. The next neuron ‘fires’ and the impulse
continues along the next neuron.
6. The impulse reaches the end of the
axon.
7. The dendrite is stimulated by the
neurotransmitting chemicals.
Correct order: ..................................................................................................................................
The nervous and endocrine system:
Summary
Explain, with the aid of the flow diagram below, what a negative feedback reaction is and
ho w an increase in blood sugar levels is controlled by such a reaction.
2. What could happen if:
(a) the speed at which a nervous system signal was greatly reduced
(b) there was a drug that suppressed the release of neurotransmitters in the body
(c) the duration of a nervous response was long-lasting
(d) the spinal cord was severed at the lower end of the spine
(e) the spinal cord was severed at the neck
(f) a person had motor neuron disease
(g) stem cell research was more advanced (e.g. stem cells could be injected into the spinal cord of
a person who had a major spinal cord injury)?
3. What is a reflex action and why is it useful? Use a flow diagram to aid your explanation.
4.
(a) Write a paragraph that summarises the function of the endocrine system. Include the
following words and phrases in your summary:
hormones
growth
endocrine glands
negative feedback mechanism
pancreas
target cell
regulate
speed of response
development
insulin
duration of response
(b) Complete the following table about the hormones and glands of the endocrine system.
Gland
Type of hormone
Effect
produced
What might happen if it
was not released?
Adrenal
Insulin
Prolactin
Controls body hair,
deepening of voice and
sexual urges
Ovaries
(females)
Affects cell growth
The endocrine system and
nervous system would not
be connected properly
5. The blue-ringed octopus is common in the waters of the South East Australian
coastline. Although it is small, when it perceives that it is in danger bright blue rings
appear on its body, giving rise to its name. It primarily eats small crustaceans, such as
crabs, and generally disables them with its very potent venom. The venom is also very
dangerous to humans. Once stung, a person almost immediately loses motor neuron
function and will eventually die of cardiac arrest (due to oxygen starvation) after a
short while.
(a) Construct a flow diagram that demonstrates the action of the respiratory system as a
stimulus response model. Although breathing is mainly regulated by carbon dioxide
levels, use a lack of oxygen as your stimulus.
(b) On your diagram, show where the blue-ringed octopus venom would have its effect.
(c) Using your knowledge of the nervous system and neurotransmitters, explain why a
sting from a blue-ringed octopus can be fatal.
Science notes
Endocrine System
The endocrine system is a collection of special organs in the body that produce hormones. These organs are usually
called the “glands.” They are located in different parts of the body.
For example, the pituitary is in the brain, the thyroid is in the neck, the adrenal glands are just alone the kidneys and
the sexual glands (ovaries and testes) are located in the sexual organs.
Each gland produces a hormone into the blood, which travels all through the body. Hormones regulate our body
activities, for example growth, sleep, sudden actions, feelings and blood sugar for energy.
All the parts of a plant or animal work together in a coordinated way. This coordination is carried out in animals by their
nervous system (as already seen) and also by special chemical substances called hormones.
For example, when excited, nervous or alarmed our heart rate increases, our muscles tighten, blood is diverted from
the digestive system to the muscles, the concentration of glucose in the blood raises slightly. All of these physiological
changes, which may result in us feeling ‘butterflies in the stomach’ or nervous, help us to respond more quickly than
we normally would. This effect is caused by the transmission of messages from the brain to different parts of the body
by the nervous system-this happens very quickly. The same effect can also be produced, but at a much slower rate, by
the secretion of hormones from the adrenal gland into the blood stream, hence the phrase ‘the adrenalin’s flowing’meaning the person is ‘pumped up’ and ready for action. (Adrenalin is know known as epinephrine and
norepinephrine).
In multicellular animals, hormones are secreted by specialised glands or by tissues. Hormones are complex molecules
that are transported throughout the body by blood or other fluids. As chemical messengers, they exert their influence
at points quite distant from their site of production. They either stimulate a particular activity in body cells or they
inhibit some activity.
Hormones regulate cellular activities and they help control the reactions of various organs so that the organs work as a
team under varying conditions. The pituitary gland, located at the base of the brain, secrets hormones that regulate
growth. If an overabundance of growth hormone is released during childhood, it produces gigantism. If insufficient
growth hormone is produced, it leads to dwarfism.
Responding To Change – A Model
For an organism to detect c__________ such as light or temperature changes, it must have
ways of d_____________ these changes. A basic scientific model for explaining how
organisms detect and r____________ to changes in their e______________ is the Stimulus
Response model:
Anything that t____________ a response of some kind is called a s____________ (plural:
stimuli). For example, a hand touches eyelashes that stimulates the t___________ receptors
at the base of the eyelash to contract m___________ causes us to b_________ (the response).
Receptors are s_____________ sensitive cells, which detect changes; these receptors are
called sense o_________ in animals. Human sense organs include e_______, e_______,
n_______, t__________ and s________. The organs, m____________ or glands that bring
about the response are called effectors. Nerves often convey the m_____________ from the
receptor to the e__________ organ. The brain and s__________ cord together make up the
central nervous s_____________.
Reflex actions such as a blink and plant growth responses such as phototropism and
geotropism fit a stimulus response model.
Nerve cells c___________ all other cells with speed (hormones are slower acting).
A nerve cell (neuron) is a specialised cell that is able to r__________ and transfer stimuli.
Neurons can be very l_______—one of the longest ones in the human body extends from the
spinal c______ (backbone) to the big t____. Nerves are b__________ of neurons—in most
living organisms they look like white cords. Different types of nerve cells carry specialised
i___________, for example, motor neurons carry impulses to m______________ and glands.
The simplest type of coordination involving nerves is a reflex response. It is automatic and
i______________ response.
Examples of a reflex response in humans is the automatic b_____________ of the eyelid
when an object suddenly appears right in front of the e_______ and the knee-jerk reflex.
A Reflex Arc
More complex arcs involve connector neurons that transmit the message from the afferent
neuron through a complex pathway in the spinal cord or brain before the impulse reaches the
motor neuron.
REFLEXES
INFORMATION
The diagram below shows the pathway through which messages (electrical impulses) travel in bringing
about the knee jerk reflex. When the tendon is tapped, receptors in the muscle are stretched and this
causes electrical impulses to be sent to the spinal cord.
QUESTIONS
1. Which structure in the diagram is the receptor? (identify it by its letter)
2. Which structure carries electrical impulses away from the spinal cord? (identify it by its letter)
3. Which structure shortens as a result of the reflex? (identify it by its letter)
4. The diagram is not drawn to scale. What would be the approximate length of the structure
labelled E in the actual reflex arc? Explain your answer.
5. Assuming that impulses travel at 100 metres per second, how many seconds would it take for
the impulses to travel right through this reflex arc?
RESPONDING AND CONTROLLING
HOMEOSTASIS is the maintenance of a constant internal environment despite changes in
the surroundings.
HOMEOSTASIS allows cells to keep working efficiently, keeping things like temperature,
glucose and water levels within carefully controlled limits.
ACTIVITY ONE: Match the stimulus with the correct receptor.
STIMULUS
Heat or cold
Water levels in the blood
Pressure and touch
Sound
Light
Chemicals
Gravity
LOCATION OF RECEPTOR
Receptors on the tongue
Cochlear cells in the inner ear
Osmoreceptors in the brain and large arteries
Thermo receptors in the skin
Receptors in the skin
Semicircular canals in the ears
Cells of the retina in the eye
ACTIVITY TWO: STIMULUS – RESPONSE MODELS.
Organise the following diagrams to show the correct stimulus-response pathway.
MODEL ONE:
EFFECTOR
Arm muscle
STIMULUS
Finger cut by knife
RECEPTOR
Pain receptors
RELAY BY NERVES
RESPONSE
Muscle contracts to withdraw
hand from knife
MODEL TWO:
COORDINATING CENTRE
The brain
RECEPTOR
Receptor cells in main arteries
RELAY BY NERVES
STIMULUS
Increase in carbon dioxide level
in blood
EFFECTOR
Diaphragm and chest muscles
FEEDBACK
Lower carbon dioxide level
RESPONSE
Increase in breathing rate
RELAY BY NERVES
MODEL THREE:
STIMULUS
Increase in body
temperature
RECEPTOR
Thermo receptors in the
skin
FEEDBACK
Decrease in body
temperature
COORDINATING CENTRE
Hypothalamus in the brain
RELAY BY NERVES
RELAY BY NERVES
RESPONSE
Increase in sweating and
blood flow to skin
EFFECTOR
Blood vessels and sweat
glands
The nervous and endocrine system
Answers
Sensory neuron
1. (a) State the function of a sensory neuron.
Sensory neurons are present in receptors and detect changes in the environment.
...................................................................................................................................................
...................................................................................................................................................
(b) Use words from
the list to label
the diagram of a
sensory neuron.
List: cell body;
axon; dendrite;
axon branches;
nucleus
Sending an impulse
2. Complete the following flow chart about the transmission of messages in the nervous system
by inserting words from the list.
List: effector; interneuron; motor neuron; receptor; sensory neuron
Neurotransmitters
3. The following diagram shows the synapse between two neurons. The lists of statements about
the transmission of the nerve impulse across the synapse are jumbled. Use the code numbers
to place the statements in the correct order.
Jumbled statements:
1. Neurotransmitter chemicals are
released.
2. Neurotransmitters reach the dendrite.
3. An impulse travels along the axon.
4. Neurotransmitters cross the synapse.
5. The next neuron ‘fires’ and the impulse
continues along the next neuron.
6. The impulse reaches the end of the
axon.
7. The dendrite is stimulated by the
neurotransmitting chemicals.
3, 6, 1, 4, 2, 7, 5
Correct order: ..................................................................................................................................
Answers
1. Negative feedback responses are those in which the response is in an opposite
direction to the stimulus. If glucose levels are too high, then a negative feedback
response would be for the body to release insulin, which would reduce the blood
sugar level.
2.
(a) The nervous signal would not move as fast and the action would reduce in speed and
efficiency. If you were trying to catch a ball, for example, although you would think
about catching it, the signal would travel slowly so your hand would probably move
after the ball had already passed you by.
(b) If a drug suppressed the release of neurotransmitters, then essentially it would be the
same as having no neurotransmitters. This would mean no movement of the nerve
impulse from one neuron to the next, which means no transfer of signal. Therefore,
the action would not take place.
(c) If the duration increases then the action would continue to happen. A new action
could not be started as the previous action is still being performed.
(d) If the spinal cord was severed at the lower back region then messages could not travel
between the lower limb region and the brain. This would mean that the person would
be unable to stand, walk or feel sensations (such as touch, heat and cold) on those
regions that have nerve connections below the sever point.
(e) If the spinal cord was severed at the neck then the nerves from regions of the body
below the sever point could not communicate with the brain. This would include the
lungs (for breathing), arm and leg movement, and so on. Actor Christopher Reeve had
a similar injury. Students may list some of the consequences experienced by him,
which are highlighted in section 3.9 of the textbook.
(f) Motor neuron disease sufferers experience degeneration of the motor neurons, which
are the neurons responsible for responding to the environment. They could sense their
environment, but are increasingly unable to respond to it.
(g) Answers will vary and this is a hypothetical question — but in theory, the aim is to
get proliferation and regeneration of spinal cord cells to aid in its repair.
3. A reflex action is an action that occurs without conscious thought. It is a survival
mechanism. It is useful because the signal is much shorter and the brain is not
involved. This comes in handy when your hand accidently touches a very hot surface,
or when an object flies quickly at your eyes. Your body reacts without hesitation,
reducing the chance of more permanent damage.
The flow diagram should resemble the diagram below from section 3.6 of the textbook.
Responding To Change – Answers A Model
For an organism to detect changes such as light or temperature changes, it must have ways of
detecting these changes. A basic scientific model for explaining how organisms detect and
respond to changes in their environment is the Stimulus response model:
Anything which triggers a response of some kind is called a stimulus (plural: stimuli). For
example, a hand touches eyelashes which stimulates the touch receptors at the base of the
eyelash to contract muscles causes us to blink (the response). Receptors are specialised
sensitive cells which detect changes, these receptors are called sense organs in animals.
Human sense organs include eyes, ears, nose, tongue and skin. The organs, muscles or glands
which bring about the response are called effectors. Nerves often convey the message from
the receptor to the effector organ. The brain and spinal cord together make up the central
nervous system.
Reflex actions such as a blink and plant growth responses such as phototropism and
geotropism fit a stimulus response model.
Nerve cells control all other cells with speed (hormones are slower acting).
A nerve cell (neuron) is a specialised cell that is able to receive and transfer stimuli. Neurons
can be very long—one of the longest ones in the human body extends from the spinal cord
(backbone) to the big toe. Nerves are bundles of neurons—in most living organisms they look
like white cords. Different types of nerve cells carry specialised impulses, for example, motor
neurons carry impulses to muscles and glands.
The simplest type of coordination involving nerves is a reflex response. It is automatic and
involuntary response.
Examples of a reflex response in humans is the automatic blinking of the eyelid when an
object suddenly appears right in front of the eye and the knee-jerk reflex.
A Reflex Arc
4.
Gland
Type of hormone
Effect
produced
Adrenal
Adrenaline and others
What might happen if
it was not released?
Raises blood pressure, heart
Blood pressure would
rate, breathing rate and
not rise, nor would the
supply of blood to muscles
heart rate, the breathing
rate or extra supply of
blood to muscles. A
quick escape would not
be possible.
Pancreas
Insulin
Increases blood glucose
Blood sugar levels
level
would not increase and
you may become
drowsy
Pituitary
Prolactin
gland
Stimulates production of
Milk would not be
milk in breasts
produced and the
mother could not feed
her baby
Testes
Testosterone
(males)
Controls body hair,
Hair would not grow,
deepening of voice and
voice would not deepen
sexual urges
and sexual urges may
not be strong
Ovaries
Oestrogen and progesterone
(females)
Controls development of
Breasts would not
breasts, prepares uterus for
develop, uterus would
zygote and controls
not be prepared and
menstrual cycle
there would be no
menstrual cycle, so a
female could not get
pregnant
Pituitary
Growth hormone
Affects cell growth
gland
Cells would not grow as
they were supposed to
and development would
be impaired
Hypothalamus
Many hormones
Connects endocrine and
The endocrine system
nervous systems
and nervous system
would not be connected
properly
5.
(a)
(b) Answer is marked in red on the diagram.
(c) The sting from a blue-ringed octopus interferes with the neurotransmitters that relay
important messages along motor neurons to target effector organs, such as the
diaphragm. In this case, the motor neurons essential for regulating breathing would
not be communicating with the relevant organ (i.e. the diaphragm) and breathing
would stop. The implications of not breathing would be that the body is starved of
oxygen and the person could die due to cardiac arrest (heart attack due to low blood
oxygen). If the person were artificially respirated (i.e. had the breathing done for them
via another person and via a machine) then the person could be kept alive until the
toxin was metabolised and the neurotransmitters would return to their normal
function.
The nervous and endocrine system
Summary
Answers
3. The human nervous system is composed of the central nervous system (the brain
and spinal
cord ) and the peripheral . nervous system (the nerves that connect the
central nervous system to the rest of the body).
4. Sensory neurons carry the information from the receptors, interneurons carry the
information through the central nervous system and motor neurons take the information
to the effectors.
5. Neurotransmitters are chemicals which pass the information across the synapse . to the
next neuron.
6. In a negative feedback mechanism , the response leads to the removal of the need for a
continued response.
7. Chemical messengers called hormones are produced in your endocrine glands and
released directly into your bloodstream.
11. The effects of the endocrine system are slower but longer lasting than those of the
nervous system.
cerebellum
brain
molecules
tissues
organs
interneurons
synapse
negative feedback
mechanism
cerebrum
peripheral
endocrine
cells
motor neurons
mind maps
spinal cord
brainstem
coordination
sensory neurons
hormones
PLASTICS REVISION TEST QUESTIONS
Circle ONE option that best answers the question.
1. The word plastic means:
a. chemical
b. able to be moulded
c. thin air
d. all of the above
2.
a.
b.
c.
d.
A monomer is a
single man
small molecule which repeats to form a polymer.
substance that can be easily moulded.
a substance that speeds up a chemical reaction.
Circle T if you think the statement is true and F if you think it is false.
1. A co-polymer is made from two different types of monomers.
T/F
2. Polymerisation is the joining of monomers to make a polymer. T/F
3. Plastic Identification codes are useful for recycling
T/F
4. Thermoplastic polymers char when heated.
T/F
5. The word monomer means many parts.
T/F
6. All types of plastics can be recycled.
7. Thermoplastic polymers have many crosslinks.
T/F
T/F
8. There are seven groups in the plastics identification code.
T/F
SHORT ANSWER QUESTIONS
1. a. What is a crosslink?
b. How do crosslinks affect the strength and flexibility of a plastic:
2. List three different environmental problems associated with plastics.
3. List 3 uses of recycled plastics.
4. Describe 3 things householders can do to assist in the recycling of plastics.
5. Explain the difference between thermosetting and thermoplastic polymers including a
comment about the difference in their melting temperatures. You must include a labeled
diagram to assist in explaining your answer. Comment on their respective melting
temperatures.
6. Name the polymers formed from the following monomers:
a) vinyl chloride
b) propene
7. Name the monomers that formed the following polymers:
a) polyethene
b) polystyrene
8. List three advantages and three disadvantages of recycling plastics.
9.
Natural Fibre
1.
2.
3.
Where it comes from
What is it used for?
Synthetic Material
What is it used for?
1.
2.
3.
10. List 7 different materials and their properties.
I.e Nylon (material) is flexible (property)
11. What do the numbers below represent?
Using the internet find 6 products that are made from recycled plastic items (List both the original
item and the recycled product).
Type of Plastic
Original plastic item
Recycled Product