Cambridge IGCSE · Biology 0610
IGCSE Biology: Gas exchange in humans — Practice Questions & Answers
Discover how the alveoli are adapted for gas exchange, how breathing moves air in and out, and how inspired and expired air differ.
486 practice questions available for this topic — here are 10 with full answers and explanations.
Start an interactive quiz on Gas exchange in humans →
Practice questions with answers
1
Multiple choice · Easy
In which structures does gas exchange take place in the human lungs?
- Alveoli
- Bronchi
- Trachea
- Larynx
Tap an answer to check it.
WhyAlveoli are the tiny air sacs where oxygen and carbon dioxide are exchanged with the blood.
2
Multiple choice · Easy
Which gas passes from the alveoli into the blood?
- Oxygen
- Carbon dioxide
- Nitrogen
- Water vapour
Tap an answer to check it.
WhyOxygen diffuses from the air in the alveoli into the blood, where it binds to haemoglobin.
3
Multiple choice · Easy
What is the common name for the trachea?
- Windpipe
- Voice box
- Food pipe
- Air sac
Tap an answer to check it.
WhyThe trachea is commonly called the windpipe; it carries air to and from the lungs.
4
Multiple choice · Easy
Which gas is present in a higher proportion in expired air than in inspired air?
- Carbon dioxide
- Oxygen
- Nitrogen
- Argon
Tap an answer to check it.
WhyExpired air contains more carbon dioxide because it is produced by respiration in the body cells.
5
Multiple choice · Easy
What is the name of the process of breathing air in and out of the lungs?
- Ventilation
- Diffusion
- Respiration
- Transpiration
Tap an answer to check it.
WhyVentilation is the movement of air into and out of the lungs caused by breathing.
6
Multiple choice · Easy
Which muscle separates the thorax (chest) from the abdomen and helps with breathing?
- Diaphragm
- Biceps
- Cardiac muscle
- Bronchiole muscle
Tap an answer to check it.
WhyThe diaphragm is a sheet of muscle below the lungs that contracts and relaxes during ventilation.
7
Multiple choice · Easy
Tiny hair-like structures that sweep mucus and trapped particles out of the airways are called what?
- Cilia
- Villi
- Alveoli
- Capillaries
Tap an answer to check it.
WhyCilia are microscopic hairs that beat to move mucus, carrying dust and microbes away from the lungs.
8
Multiple choice · Easy
During exercise, how does the breathing rate change?
- It increases
- It decreases
- It stops
- It stays the same
Tap an answer to check it.
WhyBreathing rate increases during exercise to supply more oxygen and remove more carbon dioxide.
9
Multiple choice · Medium
Which feature of alveoli increases the rate of gas exchange by providing a large surface area?
- A large number of alveoli
- A thick muscular wall
- A waterproof outer coating
- A single large air sac
Tap an answer to check it.
WhyThe presence of many millions of alveoli gives the lungs an enormous total surface area for diffusion.
10
Multiple choice · Medium
Why does each alveolus have a wall that is only one cell thick?
- To give a short diffusion distance
- To make the lungs heavier
- To store air for longer
- To prevent oxygen entering the blood
Tap an answer to check it.
WhyA thin wall creates a short diffusion distance so gases can pass quickly between air and blood.
Key terms in Gas exchange in humans
Gas exchange: The movement of oxygen and carbon dioxide between an organism and its environment by diffusion across a specialised surface.
Respiratory system: The group of organs in humans responsible for taking in air and carrying out gas exchange, including the airways and lungs.
Breathing system: Another name for the human respiratory system; the structures that move air in and out of the lungs and exchange gases.
Ventilation: The mechanical process of moving air into and out of the lungs to refresh the air around the gas exchange surface.
Breathing: The repeated movement of air in and out of the lungs caused by changes in the volume and pressure of the thorax.
Inhalation: The phase of breathing in which air is drawn into the lungs; also called inspiration.
Inspiration: Breathing in, when the thorax volume increases and air is drawn into the lungs.
Exhalation: The phase of breathing in which air is pushed out of the lungs; also called expiration.
See the full study notes and flashcards for this topic.
Practise other IGCSE Biology topics