B3.2 Transport
Practice exam-style IB Biology questions for Transport, aligned with the syllabus and grouped by topic.
Question 1
Why should a person not use their thumb when measuring a radial pulse manually?
A.
The thumb changes heart rate by stimulating the carotid artery.
B.
The thumb prevents the artery from expanding during systole.
C.
The thumb has its own detectable pulse that may interfere with the count.
D.
The thumb detects venous pressure instead of arterial pressure.
Question 2
A capillary network in an active tissue has many branches and very narrow capillaries. What exchange advantage is provided by this arrangement?
A.
It increases the total surface area and keeps diffusion distances short.
B.
It makes blood flow faster through each individual capillary.
C.
It prevents plasma from leaving the blood at any point.
D.
It increases the thickness of the wall so blood pressure is maintained.
Question 3
In a transverse section of two blood vessels, vessel X has a thick wall and a small rounded lumen, while vessel Y has a thin wall and a wide irregular lumen. What are X and Y?
A.
Both X and Y are arteries.
B.
Both X and Y are veins.
C.
X is an artery and Y is a vein.
D.
X is a vein and Y is an artery.
Question 4
What feature of many veins helps ensure that contraction of nearby skeletal muscles moves blood towards the heart?
A.
Fenestrations that rapidly filter blood plasma.
B.
A thick layer of elastic tissue that generates high pressure.
C.
A very narrow lumen that increases resistance to flow.
D.
Valves that prevent backflow of blood.
Question 5
What is the role of valves in lymph ducts?
A.
They separate oxygenated blood from deoxygenated blood.
B.
They help maintain one-way movement of lymph towards the blood circulation.
C.
They generate high pressure by rhythmic contraction of cardiac muscle.
D.
They prevent tissue fluid from entering lymph vessels.
Question 6
A student compares heart rate measured by fingertip counting at the radial pulse with a pulse oximeter.
State one unit for heart rate.
[1]
Suggest two ways to improve the reliability or fairness of the comparison.
[1]
Question 7
What is the function of elastic tissue in the wall of an artery?
A.
It stretches during ventricular systole and recoils to maintain blood pressure between heartbeats.
B.
It prevents valves in arteries from opening backwards.
C.
It forms pores that allow plasma proteins to leave the blood.
D.
It actively contracts to close the lumen completely after each heartbeat.
Question 8
What is a direct consequence of severe occlusion of a coronary artery?
A.
Increased flow through the blocked lumen due to elastic recoil.
B.
Reduced oxygen delivery to cardiac muscle supplied by that artery.
C.
Formation of tissue fluid in the aorta instead of in capillaries.
D.
Increased oxygen diffusion from the blood inside the ventricles to all cardiac muscle.
Question 9
In a young dicotyledonous stem, where is phloem usually found within a vascular bundle?
A.
In a star-shaped region at the centre of the stem.
B.
Only in the epidermis between root hairs.
C.
Towards the outside of the stem, external to the xylem.
D.
Inside the lumen of xylem vessels.
Question 10
At the arteriole end of a capillary bed, what promotes the formation of tissue fluid?
A.
Active pumping of red blood cells through the basement membrane.
B.
Contraction of lymph vessel valves at the arteriole end.
C.
Osmosis of plasma proteins out of the blood into tissues.
D.
Blood pressure forcing plasma through gaps in the capillary wall.
Question 11
What difference between blood plasma and tissue fluid is expected in healthy tissue?
A.
Tissue fluid contains more red blood cells than plasma.
B.
Tissue fluid lacks oxygen while plasma contains oxygen.
C.
Plasma lacks dissolved ions whereas tissue fluid contains them.
D.
Plasma contains more large proteins than tissue fluid.
Question 12
What distinguishes the circulation of a bony fish from that of a mammal?
A.
Fish lack capillaries, whereas mammals exchange materials only in capillaries.
B.
Fish pump blood to lungs before the body, whereas mammals pump blood to gills.
C.
Blood passes through the fish heart once per complete circuit, but through the mammalian heart twice.
D.
Fish maintain separate pulmonary and systemic circuits at different pressures.
Question 13
What adaptation of companion cells supports active loading of sucrose into phloem sieve tubes?
A.
Lignified secondary walls resisting tension.
B.
Many mitochondria providing ATP.
C.
Absence of plasma membranes to reduce resistance.
D.
Fenestrated endothelium for pressure filtration.
Question 14
State one substance that diffuses from blood into body cells via capillaries.
[1]
Outline two adaptations of capillaries for exchange.
[1]
Question 15
A student observes two blood vessels in a micrograph.
State the definition of an artery.
[1]
Distinguish an artery from a vein using two features visible in transverse section.
[1]
Question 16
Explain how veins return blood from the legs to the heart despite low blood pressure. [3]
Question 17
The diagram represents a transverse section of a young dicotyledonous root.
Identify the tissue that is usually star-shaped in the centre.
[1]
State the position of phloem in this root.
[1]
State one function of the epidermis of a root.
[1]
Question 18
Outline how the lymphatic system drains excess tissue fluid and returns it to the blood. [3]
Question 19
A student measured pulse rate manually and using a pulse oximeter after resting and after exercise.
| Condition | Trial | Manual / beats min⁻¹ | Oximeter / beats min⁻¹ |
|---|---|---|---|
| Rest | 1 | 68 | 70 |
| Rest | 2 | 72 | 73 |
| Rest | 3 | 70 | 71 |
| After exercise | 1 | 128 | 132 |
| After exercise | 2 | 134 | 136 |
| After exercise | 3 | 137 | 139 |
Compare the resting values recorded by the two methods.
[1]
Describe the effect of exercise on pulse rate.
[1]
Suggest two improvements to the method for obtaining a reliable comparison between the two methods.
[1]
Question 20
Transpiration from leaf cell walls generates tension in xylem. What property of water allows this tension to be transmitted down the xylem vessel?
A.
Active transport of water through lignified walls.
B.
Hydrolysis of water molecules in xylem sap.
C.
Cohesion between water molecules due to hydrogen bonding.
D.
Diffusion of water vapour through stomatal pores.
Question 21
What structure prevents blood flowing back into the left ventricle when ventricular pressure falls below aortic pressure?
A.
Aortic semilunar valve.
B.
Sinoatrial node.
C.
Septum.
D.
Left atrioventricular valve.
Question 22
During the cardiac cycle, left ventricular pressure has just become greater than left atrial pressure but is still lower than aortic pressure. What is the state of the left atrioventricular and aortic semilunar valves?
A.
Atrioventricular closed and semilunar open.
B.
Atrioventricular closed and semilunar closed.
C.
Atrioventricular open and semilunar closed.
D.
Atrioventricular open and semilunar open.
Question 23
How is root pressure generated in xylem vessels?
A.
Water evaporates from leaf cell walls and pulls the xylem column upward.
B.
Xylem vessel elements use ATP to pump water upward through their cytoplasm.
C.
Living root cells actively transport mineral ions into xylem, causing water to enter by osmosis.
D.
Companion cells hydrolyse sucrose to increase pressure in xylem sap.
Question 24
Explain how two tissues in artery walls help arteries transport blood away from the heart under high pressure. [3]
Question 25
Outline how an atheroma can lead to myocardial infarction.
[1]
State one risk factor associated with coronary heart disease.
[1]
Question 26
Explain how transpiration causes water to move from roots to leaves in xylem. [4]
Question 27
State what tissue fluid is.
[1]
Explain why tissue fluid is released at the arteriole end of a capillary bed and partly reabsorbed at the venule end.
[1]
Question 28
Discuss the composition of plasma and tissue fluid in relation to exchange with body cells. [4]
Question 29
Compare the circulation of blood in bony fish and mammals. [4]
Question 30
Trace the pathway of blood from the vena cava to the aorta through the mammalian heart. Include valves. [4]
Question 31
Explain why root pressure may be important at night or in very humid conditions. [3]
Question 32
Outline adaptations of phloem sieve tube elements and companion cells for translocation. [4]
Question 33
The graph shows coronary heart disease mortality and mean saturated fat intake in several populations.
Describe the overall relationship shown by the graph.
[1]
Identify one feature of the data that reduces confidence in a simple causal conclusion.
[1]
Explain one biological mechanism by which a diet high in saturated fat could increase risk of coronary heart disease.
[1]
Evaluate whether these data prove that saturated fat intake causes coronary heart disease.
[1]
Question 34
The micrograph shows transverse sections of two blood vessels.
Identify vessel X as an artery or a vein, giving one visible reason.
[1]
Identify vessel Y as an artery or a vein, giving one visible reason.
[1]
Question 35
The image shows a transverse section of a young dicotyledonous stem.
Identify the tissue labelled A.
[1]
Identify the tissue labelled B.
[1]
State one function of the tissue labelled C.
[1]
Explain one feature that supports the identification of the organ as a stem rather than a root.
[1]
Question 36
The diagrams show blood flow in a bony fish and a mammal.
State which organism has single circulation.
[1]
Compare the number of times blood passes through the heart in one complete circuit in the two organisms.
[1]
Explain one advantage of the mammalian arrangement.
[1]
Question 37
Explain how pressure changes control valve movements on the left side of the heart during ventricular systole and diastole. [4]
Question 38
A potometer was used to estimate water uptake by a leafy shoot under different air movement conditions.
State the dependent variable in the investigation.
[1]
Describe the effect of increasing air movement on water uptake.
[1]
Explain why water uptake is related to transpiration in the leaves.
[1]
Suggest one limitation of using water uptake as a measure of transpiration.
[1]
Question 39
The graph shows pressure changes in the left atrium, left ventricle and aorta during one cardiac cycle.
Identify the stage of the cycle when left ventricular pressure is highest.
[1]
State the valve event that occurs when ventricular pressure first exceeds atrial pressure.
[1]
Explain why the aortic semilunar valve opens later than the atrioventricular valve closes.
[1]
Deduce when diastolic blood pressure is measured from the graph.
[1]
Question 40
The graph shows changes in blood pressure along a capillary bed and the movement of fluid across the capillary wall.
Identify the end of the capillary bed where tissue fluid formation is greatest.
[1]
Describe how blood pressure changes from arteriole to venule end.
[1]
Explain why red blood cells and most plasma proteins are not present in tissue fluid.
[1]
Suggest what could happen if excess tissue fluid is not drained by lymph ducts.
[1]
Question 41
Seedlings were grown under different relative humidities. Root pressure in their xylem was measured at night.
Describe the relationship between relative humidity and root pressure.
[1]
State why transpiration pull is reduced at high humidity.
[1]
Explain how root pressure is generated.
[1]
Suggest why root pressure is usually insufficient to move water to the tops of tall trees during daytime.
[1]
Question 42
Outline two structural differences between arteries and veins.
[1]
Explain how arteries are adapted for transporting blood away from the heart and how veins are adapted for returning blood to the heart.
[1]
Question 43
Describe how water leaves a leaf during transpiration.
[1]
Explain how xylem structure and water properties allow water to be transported from roots to leaves.
[1]
Question 44
State the typical positions of xylem and phloem in a young dicotyledonous stem.
[1]
Compare and contrast the distribution of tissues in transverse sections of young dicotyledonous stems and roots.
[1]
Question 45
A radioactive carbon tracer was supplied to one mature leaf of a plant. Radioactivity in phloem sap was measured above and below the leaf over time.
Identify the source tissue in this investigation.
[1]
Describe the movement of labelled carbon compounds shown by the data.
[1]
Explain how loading at the source can generate pressure flow in phloem.
[1]
Suggest why companion cells near the source would have many mitochondria.
[1]
Question 46
Outline the sequence of events from atheroma formation to myocardial infarction.
[1]
Epidemiological studies may find a strong positive correlation between a lifestyle factor and coronary heart disease incidence. Evaluate the use of such data for identifying causes of coronary heart disease.
[1]
Question 47
Describe the formation of tissue fluid at the arteriole end of a capillary bed.
[1]
Discuss the composition and fate of tissue fluid after it has formed.
[1]
Question 48
Outline the roles of the atrioventricular and semilunar valves in the mammalian heart.
[1]
Explain how mammalian heart structure and the cardiac cycle deliver pressurized blood to arteries.
[1]
Question 49
Outline the pathway of blood in the single circulation of a bony fish.
[1]
Compare and contrast single circulation in bony fish with double circulation in mammals, including consequences for pressure and oxygen delivery.
[1]
Question 50
Outline three adaptations of sieve tube elements and companion cells.
[1]
Explain how phloem structure and source-sink pressure differences enable translocation of sap.
[1]
The Fast Track To Your
Best IB Coursework & College Essays
All content on this website has been developed independently from and is not endorsed by the International Baccalaureate Organization. International Baccalaureate and IB are registered trademarks owned by the International Baccalaureate Organization.