Syllabus Edition

First teaching 2014

Last exams 2024

|

The Blood System (DP IB Biology: SL)

Exam Questions

2 hours35 questions
1a
Sme Calculator
3 marks

The following diagram shows the internal structure of the heart.7Lyl7pVl_e-1a

A and C represents two heart chambers.

(i)
Label chambers A and C.

[2]

(ii)

State one difference in the function of A and C.

[1]

1b
Sme Calculator
1 mark

State the main difference between the blood found in the chambers on the left and right side of the heart.

1c
Sme Calculator
2 marks

Structure B plays an important role in the flow of blood through the heart.

(i)

Label structure B.

[1]

(ii)

State the role of structure B in the flow of blood through the heart.

[1]

1d
Sme Calculator
1 mark

Structure D is a wall of muscular tissue.

Describe the purpose of structure D in the heart.

Did this page help you?

2a
Sme Calculator
2 marks

The following diagram compares the structure of two main blood vessels in the body.

6-2-easy-q2a

(i)

Identify blood vessel A.

[1]

(ii)

State a reason for your answer in part i).

[1]

2b
Sme Calculator
2 marks

Blood vessel B has a very large lumen.

(i)

Identify blood vessel B.

[1]

(ii)

State one reason for the presence of a large lumen in blood vessel B.

[1]

2c
Sme Calculator
2 marks

The flow of blood in veins is not assisted by the pressure generated by the beating of the heart.

List two structures that assist with the flow of blood in veins.

2d
Sme Calculator
1 mark

Systolic pressure is one of the measurements taken by a doctor to determine the blood pressure of a patient.

Define the term 'systolic pressure'.

Did this page help you?

3a
Sme Calculator
2 marks

The following diagram shows part of the blood circulation of a mammal.

SKefWwjT_e-3a

(i)

Identify one example of an artery in this diagram. 

[1]

(ii)

Based on the information in the diagram, state a reason for your answer in part i).

[1]

3b
Sme Calculator
1 mark

Mammals have two separate circulations that supply blood to different organs.

State the name of the circulation that blood vessels T and S form part of.

3c
Sme Calculator
2 marks

The following table shows the mean pressure (in mmHg) measured in different blood vessels of the body.

Blood vessel Mean blood pressure / mmHg
Aorta 94
Arteries 90
Arterioles 68
Capillaries 24
Venules 10
Veins 3
Vena Cava 2

Calculate the percentage difference between the mean blood pressure of the aorta and vena cava. Show your working and give your answer to three significant figures.

3d
Sme Calculator
1 mark

Using the table provided, identify the blood vessels where the greatest decrease in mean blood pressure occurs.

Did this page help you?

4a
Sme Calculator
1 mark

The following diagram compares the structure of an artery of a healthy person with that of someone suffering from atherosclerosis.

6-2-easy-q4a

Identify structure X.

4b
Sme Calculator
1 mark

Atherosclerosis can lead to the occlusion of arteries over time.

Define the term 'occlusion'.

4c
Sme Calculator
2 marks

Occlusion of the arteries can have a serious impact on cardiovascular health.

List two consequences of an occlusion of the arteries.

4d
Sme Calculator
1 mark

When blood flow to part of the heart muscle is restricted it will impair its ability to contract fully. This will reduce blood flow, and therefore oxygen flow, to the body tissues.

State one way in which the heart will compensate for this.

Did this page help you?

5a
Sme Calculator
5 marks

One mark is available for clarity of communication throughout this question.

Atherosclerosis results in a build-up of fatty deposits known as plaque inside arteries, which may lead to coronary heart disease.

Outline the risk factors for developing atherosclerosis.

5b
Sme Calculator
3 marks

Capillaries provide the exchange surface in the tissues of the body.

List three characteristics of capillaries.

5c
Sme Calculator
6 marks

Describe the flow of oxygenated blood through the left side of the heart as it returns from the lungs.

Did this page help you?

1a2 marks

The diagram below shows part of the blood circulation in a mammal.

v84gn54O_screenshot-2023-07-12-at-10-21-39-pm

Identify the letter that represents each of the following blood vessels

Pulmonary vein   

begin mathsize 48px style square end style

Pulmonary artery      

square

1b2 marks

Explain the function of the coronary arteries.           

1c2 marks

The human circulatory system is a closed, double circulatory system.

Explain what is meant by this.

1d2 marks

Babies can sometimes be born with a small hole between the right and left ventricles of their heart.

Suggest why these babies often have problems supplying their tissues with enough oxygen.

Did this page help you?

2a1 mark

The graph below below shows changes in pressure in parts of a human heart during one second. screenshot-2023-07-13-at-6-10-31-am

Identify the time at which the semilunar valves open.

2b1 mark

Use the graph from part (a) to calculate the heart rate in beats per minute (bpm)

2c2 marks

Valves are important structures found in the heart and veins.

Explain how valves work.

2d3 marks

Ventricular systole causes an increase in pressure in the aorta shown at around 0.16 seconds in part (a)

Explain why this increase in aortic pressure is important for the organism.

Did this page help you?

3a1 mark

The graph below shows the rate of blood flow in various blood vessels in the body. It also shows the total cross-sectional area of the vessels.

YPP-3p1w_screenshot-2023-07-13-at-6-21-47-am

Suggest why the rate of blood flow increases from the venules to the vena cava despite a large decrease in the total cross-sectional area.                                                               

3b2 marks

The relative thickness of layers in the wall of an artery and a vein are shown in the table below.

Layer in wall Thickness / µm
Artery Vein
Endothelium 25 25
Smooth muscle 495 245
Elastic tissue 375 245
Connective tissue 125 125

 

Explain the difference in the thickness of elastic tissue for the artery versus the vein.

3c2 marks

The external diameter of a vein was measured at 1.5 mm. 

Calculate the diameter of the lumen of the vein.

3d3 marks

Explain how the structure of capillaries enable them to function efficiently as exchange surfaces.

Did this page help you?

4a2 marks

Plant sterols and plant stanols are found in a range of food, including vegetables,  cereals, seeds and nuts. Plant sterols and stanols have a similar structure to cholesterol and reduce the absorption of cholesterol in the small intestine, so more cholesterol is lost in the faeces. This helps to lower the levels of cholesterol in the blood and in turn, reduce the risk of coronary heart disease (CHD).

A group of scientists wanted to investigate the effects of eating plant sterols and stanols on the risk of CHD. The scientists randomly divided healthy volunteers into two groups. Every day for eight weeks, one group was given plant sterols and stanols to eat. The other group acted as a control.

Each week, the scientists measured the diameter of the lumen of the main artery in the arm of the volunteers.

State how the control group should have been treated.

4b3 marks

The results of the experiment in part (a) are shown in the table below.

  Mean maximum diameter of lumen of main artery in the arm (mm)

Experimental group

(± standard deviation)

Control group

(± standard deviation)

Before experiment 0.69 (± 0.02) 0.71 (± 0.02)
After 8 weeks 0.74 (± 0.03) 0.72 (± 0.05)

 

A student reading the results concluded that there was sufficient evidence to assume a causal relationship between plant sterols and stanols, and a reduced risk of CHD.

Evaluate the student’s conclusion.

4c2 marks

An electrocardiogram (ECG) measures the electrical fluctuation within a cardiac muscle as a heart is beating. The diagram below shows an ECG trace for a normal, healthy person and an ECG trace for a person suffering from heart disease.

Figure 1-poqm_qH_ma4c-6-2-the-blood-system-medium-ib-hl-biology-sq

Describe the path that electrical impulses follow when they are transmitted from the sinoatrial node to cause contraction in the ventricular muscle in a healthy heart.

4d2 marks

Suggest how the information from part (c) shows that the damage caused to the diseased heart is likely to have affected the sinoatrial node (SAN).

Did this page help you?

5a6 marks

One mark is available for clarity of communication throughout this question.

Explain what causes heart rate to increase during exercise.

5b4 marks

Describe how blood returns to the heart from the legs.

5c5 marks

Outline William Harvey’s theories about circulation

Did this page help you?

1a
Sme Calculator
2 marks

Based on your knowledge of diffusion, explain why multicellular organisms need a specialised transport system.

1b
Sme Calculator
2 marks

The following table shows the volume of blood present in the left ventricle of a person at different times over the course of one second.

Time / s Volume of blood in left ventricle / cm3
0.0 105
0.1 117
0.2 89
0.3 63
0.4 45
0.5 55
0.6 87
0.7 105
0.8 119
0.9 90
1.0 62

Use the information in the table to calculate the heart rate (beats min-1) of this person. Show your working.

1c
Sme Calculator
2 marks

During ventricular systole, the muscular wall of the ventricles contract.

(i)

Based on the information provided in the table in part a), determine during which time interval(s) the heart was in ventricular systole.

[1]

(ii)

Explain your answer in part i).

[1]

Did this page help you?

2a
Sme Calculator
3 marks

A group of students investigated the effect of a person's fitness level on the heart rate before, during and after exercising. They measured the resting heart rate of an unfit person leading a sedentary lifestyle and that of a trained athlete. After monitoring their resting heart rate for 10 minutes, both participants were asked to run for a period of 10 minutes. Their heart rates were monitored during this time by a heart rate monitor that was attached to their wrists. After exercising, their heart rates were monitored for a period of 40 minutes.

The results of this investigation is shown in the following graph.

Y8Z2iXwH_h-2a

Contrast the results of the two participants.

2b
Sme Calculator
3 marks

Explain the mechanisms that caused the change in heart rate that was observed after the exercise ended.

2c
Sme Calculator
3 marks

The group of students concluded that an increased fitness level enables the heart to recover more quickly after exercise.

Evaluate the conclusion of the students.

Did this page help you?

3a
Sme Calculator
2 marks

Ebstein's anomaly is a birth defect where the tricuspid valve is displaced from its normal position between the right atrium and ventricle. This defect will often cause the valve to not function properly. Babies born with Ebstein's anomaly will require surgery to correct the defect.

The following diagram compares the structure of a normal heart with the heart of a person born with Ebstein's anomaly.h-3a-1

Explain the effect that a faulty heart valve may have on the flow of blood through the right side of the heart.

3b
Sme Calculator
2 marks

Babies born with Ebstein's anomaly will often develop an enlarged heart and swollen limbs once they reach adulthood.

Based on the information provided in part a), suggest a reason for each of these symptoms.

3c
Sme Calculator
2 marks

Tricuspid valve surgery is a very effective way to treat patients born with Ebstein's anomaly and restore heart function back to normal. One way to measure the effectiveness of this treatment is to investigate the increase in cardiac output before and after surgery.

Cardiac output is the amount of blood that the heart pumps per minute.

A patient born with Ebstein's anomaly has a mean heart rate of 78 beats per minute and with every heart beat, 45 cm3 of blood leaves the heart.

Calculate the cardiac output (dm3min-1) of this patient. Show your working.

3d
Sme Calculator
1 mark

After the surgery, the cardiac output of the patient from part c) increased by 25%.

Calculate the cardiac output (dm3min-1) after surgery.

Did this page help you?

4a
Sme Calculator
2 marks

Carnitine is a chemical that plays an essential role in energy metabolism by transporting long-chain fatty acids into mitochondria in cells where they are then oxidised. It is often used as a supplement by athletes to enhance their athletic performance and to aid in weight loss.

Recent studies have linked the prolonged use of carnitine supplements with increased levels of trimethylamine N-oxide (TMAO) in the bloodstream. TMAOs can trigger inflammatory and immune responses in the body, as well as elevated blood glucose levels.

Based on the information provided, explain why increased TMAO levels could increase the risk of suffering a heart attack.

4b
Sme Calculator
1 mark

Scientists investigated the effect of carnitine in the diet on the plasma concentration of TMAO in mice. Four groups, consisting of ten mice each, were fed one of four possible diets.

  • Diet 1 - a normal mouse diet with natural carnitine levels 
  • Diet 2 - a normal mouse diet with added carnitine
  • Diet 3 - a low carnitine mouse diet
  • Diet 4 - a normal mouse diet with added carnitine and antibiotics

The TMAO levels in the bloodstream of the mice were measured over time and a mean for each group was calculated.

Suggest a possible hypothesis for this investigation.

4c
Sme Calculator
1 mark

The results of the investigation described at part b) are shown in the following graph.

RkEvF74L_h-4c

Explain the results from the group that followed diet 4.

4d
Sme Calculator
3 marks

The scientists concluded that a diet high in carnitine will increase levels of TMAO in the bloodstream in humans.

Evaluate this conclusion.

Did this page help you?

5a
Sme Calculator
3 marks

One mark is available for clarity of communication throughout this question.

The sinoatrial node (SAN) is considered to be the pacemaker of the heart.

Explain this statement.

5b
Sme Calculator
7 marks

Outline the pressure changes that occur during one cardiac cycle and the effect this has on the valves in the heart.

Did this page help you?