1. Module 3: Section 1: Exchange Surfaces
3.1 Exchange between organisms and their environment:
How does the size of an organism and its structure relate to its surface area to volume ratio?
How do larger organisms increase their surface area to volume ratio?
How are surfaces specially adapted to facilitate exchange?
Key words:
diffusion; osmosis; surface area to volume ratio;
List examples of things that need to be interchanged between an organism and it’s environment:
How would you calculate the surface area and volume of a cube?
Surface area: Volume:
How would you calculate the surface area and volume of a sphere?
Compare a cube of 1cm3 to a cube of 6cm3 I in terms of their surface area:volume.
Desribe some surfaces and how they are adapted to facilitate exchange:

2. Module 3: Section 1: Exchange Surfaces
3.1 Gas exchange in single-celled organisms and insects:
How do single celled organisms exchange gases?
Why do some organisms need a specialised gas exchange system?
What are the features of an efficient gas exchange system?
How do insects carry out gas exchange?
Key words:
Surface area : Volume ratio; spiracles; diffusion distance; trachea; thoracic movement; abdominal movement; tracheal fluid; tracheoles;
How does gas exchange take place in this single celled organism?
Why can this organism rely on this form of gas exchange?
Label the insect gas exchange system below:
How do they prevent
water loss?
Do their gases
diffuse into the
bloodstream?
How can gas exchange
be increased?
Label the abdomen and thorax.
Explain how an insect carries out ventilation using the graphs:
Larger organisms will need a specialised. gas exchange surface.
They do this by doing 3 things: Annotate diagrams. 1.
2. and an efficient ventilation mechanism.
3 Thin gas exchange surface – give 2 examples:

3. Module 3: Section 1: Exchange Surfaces
3.1 Gas exchange in fish:
What is the structure of fish gills?
How is water passed along fish gills?
What is the difference between parallel flow and countercurrent flow?
How does countercurrent flow increase the rate of gas exchange?
Key words:
countercurrent flow; operculum; buccal cavity; gill arch; gill filaments; gill lamellae;
Label a gill arch, gill filaments and gill plates.
Annotate the diagrams to show direction of blood flow and water flow.
Describe parallel flow and countercurrent flow:
Complete the gaps in the table:
Bringing water into the Buccal Cavity
Pushing water over the gills
Mouth Opens
Mouth
Operculum
Buccal cavity
Floor
Decreases
Increase in
Water is forced over gills
Water is drawn in

4. Module 3: Section 1: Exchange Surfaces
3.1 Mammalian Gas Exchange Systems
Know about the structures of a mammalian gas exchange
Know about the functions of the different tissue and their locations in the mammalian gas exchange system
Key words: cartilage; ciliated epithelium; goblet cells; smooth muscle; elastic fibres; intercostal muscles (internal and external);
trachea; bronchi; bronchioles; diaphragm;
Label the lungs:
Tissues found within the lungs and their functions:
Label the ciliated epithelial
cells and goblet cells.
Where are they found in the lungs?
What do they do?
Cartilage, smooth muscle and elastic fibres are tissues found within the lungs.
Where is cartilage found in the lungs and what is its purpose?
Smooth muscle like all muscle tissue can contract and relax. By contracting the smooth muscle tissue can cause the bronchi and bronchioles to narrow.
Elastic fibres give the property to structures of stretch and recoil. Explain the terms stretch and recoil.
Elastic fibres are found in the alveoli – why might this be useful?

5. Module 3: Section 1: Exchange Surfaces
3.1 The mechanism of breathing:
How is air moved into the lung when breathing in?
How is air moved out of the lungs when breathing out?
What is meant by pulmonary ventilation and how is it calculated?
Key words: diaphragm; expiration; external intercostal muscles; inspiration; internal intercostal muscles; pulmonary ventilation; tidal volume; vital capacity, breathing rate; oxygen uptake.
What is a spirometer?
The vital capacity of the lungs equals the sum of 3 things, what are these?
Label the diagrams above as inspiration or expiration.
Inspiration
Expiration
External Intercostal muscles
Internal Intercostal muscles
Thoracic volume
Thoracic Pressure
Air moves
Use the diagram above to explain the following:
Tidal volume:
Inspiratory reserve volume:
Expiratory reserve volume:
Vital capacity:
What is the residual volume?

6. Module 3: Section 1: Exchange Surfaces
Exam questions
The diagram shows the position of the diaphragm at times P and Q.
Describe what happens to the diaphragm between times P and Q to bring about the change in its shape.
(2 marks)
Air moves into the lungs between times P and Q. Explain how the diaphragm causes this.
(3 marks)
Describe how oxygen in air in the alveoli enters the blood in capillaries.
(2 marks)

7. Module 3: Section 1: Exchange Surfaces
Exam questions
The graph shows changes in the volume of air in a person’s lungs during breathing.
The person was breathing in between times A and B on the graph.
Explain how the graph shows that the person was breathing in between times A and B.
(1 mark)
Describe and explain what happens to the shape of the diaphragm between times A and B.
(2 marks)
The person’s pulmonary ventilation changed between times C and D. Describe how the graph shows that the pulmonary ventilation changed.
(3 marks)

8. Module 3: Section 1: Exchange Surfaces
Exam questions
A fish uses its gills to absorb oxygen from water. Explain how the gills of a fish are adapted for efficient gas exchange.
(6 marks)
The body of a flatworm is adapted for efficient gas exchange between the water and the cells inside the body.
Using the diagram, explain how two features of the flatworm’s body allow efficient gas
exchange. 1 2
(2 marks)

9. Module 3: Section 2: Transport in Animals
3.2 The Need for a Transport System in Multicellular Organisms
Why do larger multicellular organisms need a transport system?
What are the different types of circulatory systems?
What are the advantages of having a circulatory system?
Key words:
diffusion; metabolic rate; surface area: volume single and double circulatory systems; open and closed circulatory systems.
Explain why large organisms need a complex transport system:
Label the diagrams as single or double and indicate whether it would be found in fish or mammals.
Define single circulatory system:
Define double circulatory system:
What are the advantages offered by a double circulatory system>
What type of transport system is this?
What type of animal has this
type?
Describe the features of this system (pressure and direction)
Does this system have a distinct
blood & tissue fluid?
(explain)
Fish and mammals both have closed circulatory systems, give 3 key differences between an open and closed system:

10. Module 3: Section 2: Transport in Animals
3.2 The structure and function of arteries, arterioles, capillaries, venules and veins.
What tissues are found in the walls of the different blood vessels and how do they adapt a blood vessel to its function?
Key words: collagen; elastic fibres; smooth muscle; tissue fluid; lymph vessels; lymph; hydrostatic pressure; oncotic pressure;
Identify whether the blood vessels below are an artery, vein or capillary.
Label the tunica externa, tunica media and tunica intima and annotate the tissues that are found in each.
What properties does collagen give to a blood vessel wall?
What properties does elastin give to a blood vessel wall?
Why is the endothelium of an artery folded?
Describe the structure of a capillary – how is it adapted for its function?
Describe how an artery is constructed to cope with high pressure, pulsating blood:
How does the structure and position of the veins help with returning low pressure blood back to the heart?
Tissue fluid is formed when water and small molecules pass out the arterial end of capillaries
The diagram shows some pressures involved.
Label the arrows
on the diagram.
Cells are bathed in tissue fluid and exchange takes place.
Name 3 materials that are exchanged:
What is an oedema and why might high blood pressure cause this?
About 15% of the tissue fluid does not return to the capillaries, where does it go?
Component
Blood Plasma
Tissue Fluid
Lymph
Erythrocytes
Lymphocytes
Phagocytes
Fats / Glucose
Gases

11. Module 3: Section 2: Transport in Animals
3.2 The structure of the heart:
What is the appearance of the heart and its associated blood vessels?
Why is the heart made up of two adjacent pumps?
How is the structure of the heart related to its functions?
Key words:
aorta; atrioventricular valves; atrium; bicuspid; coronary arteries; pulmonary artery; pulmonary vein; tricuspid; vena cava; ventricle; coronary arteries.
Label the parts of the heart: left and right ventricles and atria; pulmonary artery and vein; tricuspid and bicuspid valves; tendinous cords; semi-lunar valves; aorta; vena cava.
Explain the difference in wall thicknesses between atria and ventricles:
Explain the differences in wall thicknesses between the left and right ventricles:
What runs across the surface of the heart and how can they be affected by diet?
This diagram is looking down at a transverse cut of the heart, identify x and y.

12. Module 3: Section 2: Transport in Animals
3.2 The cardiac cycle:
What are the stages of the cardiac cycle?
How do the valves control the flow of blood through the heart?
Be able to use a graph showing pressure and volume changes to be able to follow the flow of blood from one chamber to the next.
Key words: atrial systole; cardiac cycle; diastole; pocket valves; semi-lunar valves; ventricular systole;
Label the main features of the cardiac cycle:
Annotate the graph with the following: left atrium; left ventricle; aorta; semi-lunar valves opening; semi-lunar valves closing; lup and dup; atrioventricular valves opening and closing; atria filling with blood; aorta filling with blood; ventricle emptying.
Explain diastole:
Explain atrial systole:
Explain ventricular systole:

13. Module 3: Section 2: Transport in Animals
3.2 How heart action is initiated and coordinated:
Know the roles of the sino-atrial(SAN) and atrio-ventricular nodes(AVN) in coordinating the heart beat;
Be able to identify the main components of an ECG and be able to identify tachycardia; bradycardia; fibrillation and an ectopic heart beat.
Key words: SAN; AVN; bundle of his; purkyne fibres; wall of non-conducting tissue; wave of depolarisation; apex; electrocardiogram;
An electrocardiogram can be used to show the passage of electrical activity over the surface of the heart.
What section shows
when the ventricles
contract?
When the ventricles
are relaxing?
When the atria are contracting?
What is the heart rate in bpm?
Cardiac muscle is described as being myogenic, what does this mean?
The top ECG is ‘normal’
What are the other 2 showing?

14. Module 3: Section 2: Transport in Animals
3.2 Understand the role of haemoglobin in transporting gases.
Key words: partial pressure; affinity; associate; dissociate; haemoglobin; oxyhameoglobin; oxygen dissociation curve;
Define partial pressure:
What is the name of this curve?
What is formed when oxygen combines with haemoglobin?
Why is the curve sigmoid shaped?
Why is it physiologically important to be sigmoid shaped?
Fetal Haemoglobin
Does fetal haemoglobin have a higher or lower affinity for oxygen?
What is the partial pressure of oxygen like at the placenta?
At a PP of 5KPa what % of maternal and fetal haemoglobin is saturated with oxygen?
This oxygen will be able to diffuse across the placental and will attach to fetal hameoglobin.

15. Module 3: Section 2: Transport in Animals
3.2 Understand the role of haemoglobin in transporting carbon dioxide and the effect that carbon dioxide has on the affinity of haemoglobin for oxygen.
Key words: chloride ion shift; Bohr shift; haemoglobinic acid; hydrogen carbonate ions; carbaminohaemoglobin;
Where in the body will there be a high partial pressure of CO2?
Does the affinity of haemoglobin increase or decrease if the ppCO2 increases?
Which direction does the oxygen dissociation curve move when the ppCO2 increases?
Why is this physiologically useful?
Carbon dioxide only dissolves very slowly in water. However, in red blood cells it dissolves rapidly, helping to maintain a steep concentration gradient, suggest why.
Name ion X which enters the red blood cell.
Explain why it moves into the red blood cell.
Use steps 6,7 and 8 to explain why a high CO2 concentration I tissues causes the BOHR shift (haemoglobin to reduce its affinity for oxygen.
How else is CO2 transported in the blood?

16. Module 3: Section 2: Transport in Animals
Exam questions
The diagram shows a human heart as seen from the front. The main blood vessels are labelled D to G. The arrows show the pathways taken by the electrical activity involved in coordinating the heartbeat in the cardiac cycle.
Which of the blood vessels, D to G
carries oxygenated blood to the heart
(1 mark)
carries deoxygenated blood to the lungs?
Explain, in terms of pressure, why the semilunar valves open.
(1 mark)
When a wave of electrical activity reaches the AVN, there is a short delay before a new wave leaves the AVN. Explain the importance of this short delay.
(2 marks)

17. Module 3: Section 2: Transport in Animals
Exam questions
The table shows pressure changes in the left side of the heart during one cardiac
cycle.
Between which times is the valve between the atrium and the ventricle closed?
Explain your answer.
Times ……………… s and ………………… s
Explanation
(2 marks)
The maximum pressure in the ventricle is much higher than that in the atrium.
Explain what causes this.
(2 marks)
Use the information in the table to calculate the heart rate in beats per minute.
Answer beats per minute
(1 mark)

18. Module 3: Section 2: Transport in Animals
Exam questions
The diagram shows some of the large blood vessels in a mammal.
Add arrows to the diagram to show the direction of blood flow in each of the blood vessels A-E
(1 mark)
Which of blood vessels A to E is the hepatic portal vein?
Which of blood vessels A to E contains blood at low pressure?
Complete the table to show two differences between the structure of vessel C and E
(2 marks)
Blood vessel B contains smooth muscle in its walls. Explain how this muscle may reduce the blood flow to the small intestine
Elastic tissue in the wall of blood vessel A helps to even out the pressure of blood through this vessel. Explain how.

19. Module 3: Section 3: Transport in Plants
Be able to label the tissues found in a leaf, stem and root
Know the features of a plan diagram
Know the structure and functions of different vascular tissues; xylem vessels; sieve tube elements and companion cells
Key words: xylem vessels; sieve tube elements; companion cells; epidermis; endodermis; cambium; vascular bundle; endodermis; cortex; pith; root hair; palisade mesophyll; spongy mesophyll; lower and upper epidermis;
Below are diagrams of a transverse section of a root and a stem. They are plan diagrams. Label them appropriately and annotate them with the following labels:
epidermis / cortex / pith / endodermis / xylem / phloem / vascular bundle / cambium
What are the features of a plan diagram?
Draw and label a plan diagram to show the transverse section of a dicotyledonous leaf:
Xylem Vessel
Label and annotate to show
the features and how this
adapts it to its function.
Sieve Tube Elements
& Companion Cells

20. Module 3: Section 3: Transport in Plants
3.1.1 Movement of water through roots:
How is water taken up be the root hairs?
How does water pass through the cortex of a root?
What are the apoplastic and symplastic pathways?
How is water passed through the endodermis into the xylem?
Key words:
root hairs; transpiration; water potential; cohesive; osmosis; diffusion; carrier proteins; Casparian strip; endodermal cell; xylem; root pressure; cell wall; cytoplasm; symplast; apoplast; cohesion; adhesion; root pressure;
Water will move into the root via the root hair cell. It will then travel across the cortex via the apoplastic and symplastic pathways – clearly draw these and label them onto the diagram.
Is water moving by diffusion or osmosis in the
apoplast pathway, explain your answer:
Label the structures Q and R.
What process is being shown at T?
What is the purpose of the Casparian strip?
Endodermal cells actively pump ions into the xylem vessels, what will this do to the water potential inside the xylem vessels?
What is root pressure?
How could you prove that the generation of root pressure is an active process?

21. Module 3: Section 3: Transport in Plants
3.1.3 Movement of water up stems:
What is transpiration?
How does water move through the leaf?
How does water move up the xylem?
Key words:
Osmosis; cohesion-tension theory; transpiration; guard cells; stomatal pores;
Annotate and label the diagram to show the process of transpiration.
Include the following: endodermic; casparian strip; cohesion; adhesion; column of water molecules; tension created by evaporation; symplast and apoplast pathways in the leaf and root;
Define transpiration:
What is meant by the transpiration stream?
What is a simpler word for tension?
Why is transpiration inevitable?
The transpiration stream is explained using the
Cohesion-tension theory, explain this:

22. Module 3: Section 3: Transport in Plants
3.1.3 Transpiration and factors affecting it:
Why does transpiration occur?
How does external factors such as light, temperature, humidity and air movement affect transpiration?
Key words:
diffusion; light; temperature; relative humidity; potometer; wind speed.
Draw 3 graphs to aid an explanation as to how temperature, relative humidity and wind speed affect the rate of transpiration:
Explain how this potometer works:
Explain the function of the water reservoir:
Explain three precautions that need to be taken when using a potometer:
Explain why the measurements obtained will not be an accurate reflection of the rate of transpiration?

23. Module 3: Section 3: Transport in Plants
3.3 Plant Adaptations to Water Availability:
How do terrestrial plants balance the need for gas exchange and the need to conserve water?
How do plants adapt to living in areas where water loss form transpiration may exceed their water intake?
What are xerophytic features? What are hydrophytes and what adaptations do they show?
Key words:
stomata; xerophytes; cuticle; water potential; transpiration; transpiration; stomatal density; aerenchyma; hydrophyte; parenchyma.
What is a xerophyte?
Give 3 examples of plants that would show xeromorphic adaptations:
Explain how the following adaptations would help with water conservation, where applicable point out any possible drawbacks as well:
Hairy leaves
Reduced leaves
Succulents(storing water in parenchyma tissue)
Leaf loss
Hydrophytes are plants that live in water.
Give 3 examples of plants that are hydrophytes:
Explain why hydrophytes often show the following adaptations:
Very thin or no waxy cuticle:
Stomata on upper rather than lower surfaces:
Aerenchyma in leaves, stems and roots:
Small roots:

24. Module 3: Section 3: Transport in Plants
3.3 Translocation
Describe how sucrose can move passively into the phloem sieve elements using the symplast route.
Be able to describe how ATP and cotransport is used to move sucrose into the phloem sieve elements at the source.
Be able to explain how pressure gradients are created between sources and sink.
Be able to describe 3 pieces of evidence that support the mass flow/ pressure flow hypothesis
Know that sucrose is unloaded at the sinks through a process of facilitated diffusion.
Key words: companion cells; sieve tube elements; plasmodesmata; water potential; facilitated diffusion; cotransport; sink; source; assimilate; sucrose;
Translocation can be defined as the movement of assimilates from a source to a sink.
What are assimilates and give 2 examples
Define a source and give 2 examples
Define a sink and give 2 examples
On the right is a diagram which tries to explain the pressure flow hypothesis:
Add annotations to show where and why water will move in.
Add labels to show where there would be high and low hydrostatic pressure
Explain how sucrose is brought into the cell using ATP and a cotransporter molecule
How will sucrose reach the sieve tube elements from the companion cells?
The pressure flow / mass flow hypothesis is the best explanation yet of translocation. Describe 3 pieces of evidence that can support this theory:

25. Module 3: Section 3: Transport in Plants
Exam questions
A student investigated the rate of transpiration from a leafy shoot. She used a potometer to measure the rate of water uptake by the shoot. The diagram shows the potometer used by the student.
Give one environmental factor that the student should have kept constant during this investigation.
(1 mark)
The student cut the shoot and put it into the potometer under water. Explain why.
The student wanted to calculate the rate of water uptake by the shoot in cm3 per minute. What measurements did she need to make?
(2 marks)
The student assumed that water uptake was equivalent to the rate of transpiration. Give two reasons why this might not be a valid assumption. 1. 2.