Practice 6.4 Gas exchange 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.[5]
All organisms take in and also release carbon compounds. Draw a labelled diagram of the carbon cycle.
2.[6]
Describe how the rate of photosynthesis can be measured.
3.[7]
Explain the mechanism of ventilation in humans.
Question 2
SLPaper 1A
During expiration, how does air pressure in the lungs compare with atmospheric pressure?
Question 3
SLPaper 1A
What change occurs to the pressure and volume of the lungs when the external intercostal muscles contract?
Question 4
SLPaper 1A
What conditions are necessary for air to be exhaled from the lungs?
Question 5
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 6
SLPaper 2
1.[4]
Draw a labelled diagram of the heart showing the chambers, associated blood vessels and valves.
2.[6]
Describe the relationship between the structure and function of blood vessels.
3.[8]
Explain the mechanisms involved in the ventilation of the lungs.
Question 7
HLPaper 1A
What is produced by type II pneumocytes?
Question 8
SLPaper 2
1.[5]
State the functions of the following organelles of a eukaryotic animal cell: lysosome, Golgi apparatus, free ribosomes, plasma membrane, rough endoplasmic reticulum.
2.[4]
Distinguish between anaerobic and aerobic cell respiration in eukaryotes.
3.[9]
Explain the mechanism of ventilation in the lungs in order to promote gas exchange for cell respiration.
Question 9
SLPaper 1A
Which of the following features is essential for alveoli to function?
Question 10
SLPaper 1A
What occurs during inhalation?
| External intercostal muscles | Movement of ribs | |
|---|---|---|
| A. | relax | fall |
| B. | contract | fall |
| C. | relax | rise |
| D. | contract | rise |