Practice 6.2 The blood system with authentic IB Biology exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like cell biology, genetics, and ecology. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
SLPaper 2
1.[6]
Draw a labelled diagram of the human heart showing the attached blood vessels.
2.[5]
Describe the action of the heart in pumping blood.
3.[7]
Nerves connecting the brain and heart contain neurons that control heart rate. Explain how a nerve message passes from one neuron to another neuron.
Question 2
SLPaper 2
The structure of part of the digestive system is shown in the diagram below. 
[Source: https://wccyusoueahdpdicsyrg.supabase.co/storage/v1/object/public/question-images/images/69c87bb4-31dd-4a17-a292-cd2edda2d48f.jpg Created by Wikipedia user: Madhero88.]
1.[1]
Label the diagram to show the structure that is involved in digestion of proteins in acid conditions (using the letter A).
2.[1]
Label the diagram to show the structure where most absorption of water to prevent dehydration occurs (using the letter B).
3.[1]
Label the diagram to show the structure where most absorption of nutrients occurs (using the letter C).
4.[2]
Explain how the structure of veins is adapted to their function.
5.[2]
Cells defend the body against pathogens. Outline how some of these cells ingest pathogens in the blood and in body tissues.
Question 3
HLPaper 1A
Which of the following is transported by the blood?
Question 4
HLPaper 1A
What occurs as a result of a cut in the skin of a finger?
Question 5
HLPaper 1A
What is the sequence of events in blood clotting after the platelets have been activated?
Question 6
HLPaper 2
1.[4]
Draw a labelled diagram of the heart showing the chambers, associated blood vessels and valves.
2.[6]
Describe the processes involved in blood clotting.
3.[8]
Discuss the benefits and risks associated with vaccination programmes.
Question 7
HLPaper 1A
Which sequence will result in the formation of a blood clot?
Question 8
SLPaper 2
1.[4]
Describe the properties of water that make it a useful component of blood.
2.[6]
Explain the relationship between structure and function of arteries, capillaries and veins.
3.[6]
Outline how leucocytes defend the body against pathogens.
Question 9
SLPaper 2
Medical scientists investigated the development of nephrotic syndrome, a kidney disease that results in the abnormal presence of protein in the urine. This symptom of the disease can also be caused by injecting puromycin aminonucleoside (PAN) into rats. The drug edaravone, a proposed treatment for the disease, was studied. The experimental timetable for the different treatment groups is summarized below. Edaravone was given by mouth (oral dose). Saline is a solution with the same concentration of solutes as blood plasma. 
[Source: H. Matsumura, Ashida, K. Hirano, H. Nakakura and H. Tamai, "Protective effect of radical scavenger edaravone against puromycin nephrosis", Clinical Nephrology, Vol. 66, no. 6/2006, pp. 405-410. Reprinted with permission.] The graph below shows the levels of protein found in the urine of the rats on day 3, day 6 and day 9 of the experiment. 
[Source: H. Matsumura, Ashida, K. Hirano, H. Nakakura and H. Tamai, "Protective effect of radical scavenger edaravone against puromycin nephrosis", Clinical Nephrology, Vol. 66, no. 6/2006, pp. 405-410. Reprinted with permission.]
1.[1]
State when PAN was injected into the rats.
2.[2]
Outline the treatment given to the control group.
3.[1]
Distinguish between the treatment received by the PAN only group and the PAN + early edaravone group.
4.[1]
State the increase in protein in the urine of rats treated with PAN only between day 6 and day 9.
5.[2]
Compare the levels of protein during the experiment in the urine of rats treated using PAN only with those treated using PAN + early edaravone.
6.[2]
Evaluate whether the results support the hypothesis that a continuous dose of edaravone is better than the same drug administered over shorter periods.
Question 10
SLPaper 1A
What is an advantage of capillary walls being one cell thick in the systemic circulation?