DP IB Biology: SL

Topic Questions

Syllabus Edition

First teaching 2014

Last exams 2024

|

6.4 Gas Exchange

1
Sme Calculator
1 mark

Which row of the table describes the best overall conditions for gas exchange in the lungs?

  Surface Area Diffusion Pathway Concentration Gradient
A. Large Long Steep
B. Large Short Steep
C. Large Short Shallow
D. Small Short Shallow

Did this page help you?

2
Sme Calculator
1 mark

Which row of the table shows the events of inspiration in the correct sequence?

  1 2 3 4
A. Diaphragm and external intercostal muscles contract Volume of thorax increases Thorax pressure drops Air is drawn into the lungs down its pressure gradient
B. Thorax expands Thorax pressure drops Diaphragm and external intercostal muscles contract Volume of thorax increases
C. Air is drawn into the lungs down its pressure gradient Diaphragm and external intercostal muscles contract Thorax pressure drops Volume of thorax increases
D. Thorax pressure drops Volume of thorax increases Thorax expands Air is drawn into the lungs down its pressure gradient

Did this page help you?

3
Sme Calculator
1 mark

Which of the following is a feature of forced expiration?

  • The diaphragm contracts.

  • The thorax undergoes a drop in pressure. 

  • The internal intercostal muscles contract. 

  • The external intercostal muscles contract.

Did this page help you?

4
Sme Calculator
1 mark

Which aspects of ventilation are assisted by the solution secreted by type II pneumocytes?

  1. Dissolving of oxygen gas.

  2. Recoil of alveolar walls during expiration.

  3. Preventing alveoli from collapsing.

  4. Diffusion of carbon dioxide gas into the alveoli.

  • I, II, and IV only.

  • I and IV only.

  • I, III, and IV only.

  • I and III only.

Did this page help you?

5
Sme Calculator
1 mark

Patients with emphysema are often prescribed oxygen cylinders to breathe from. The oxygen concentration in a cylinder is around 90%, compared to 21% in atmospheric air. 

How does breathing concentrated oxygen increase the effectiveness of the lungs?

  • Increases concentration gradient.

  • Assists expiration of stale air. 

  • Makes breathing easier.

  • Decreases diffusion pathway. 

Did this page help you?

1
Sme Calculator
1 mark

During a gas exchange investigation, measurements were recorded from four animals that were observed as they breathed normally over a period of 5 minutes. Note that the efficiency of gas exchange was the same in all four animals and that tidal volume refers to the volume of air that moves into the lungs with each normal breath.

Which animal had the highest oxygen intake during five minutes of normal breathing?

Animal Tidal volume / dm3 Breathing rate / breaths per minute
A. 0.2 10
B. 0.6 20
C. 0.5 18
D. 0.33 24

Did this page help you?

2
Sme Calculator
1 mark

Which row of the table contains five correct statements about forced expiration?

  Ribs Diaphragm Pressure in thorax External intercostal muscles Internal intercostal muscles
A. Move down and inwards Contracts Increases Relax Relax
B. Move down and inwards Relaxes Increases Relax Contract
C. Move down and inwards Relaxes Decreases Recoil Contract
D. Move up and outwards Contracts Decreases Contract Contract 

Did this page help you?

3
Sme Calculator
1 mark

Four patients, all male and in the age range 60-65, visited their family doctor complaining of breathing difficulties. The doctor asked each man a series of questions about his symptoms and lifestyle. 

Based upon the men's lifestyles and their lists of symptoms, which patient is at the highest risk of lung cancer?

Patient Smoker / how many cigarettes? Coughing? Fatigue? Appetite? Other
A. Yes - 20 per day since age 18 Yes - sometimes with blood Every day Poor Worked with asbestos in his 20s
B. Yes - 5 per day since age 18 Yes - frequent No High BMI = 39
C. No Yes - especially at night Occasionally Normal Dry, flaky skin
D. 40 years at 20 per day but quit smoking completely 5 years ago Yes - persistent colds and coughs Occasionally Poor Chest pains

Did this page help you?

4
Sme Calculator
1 mark

Anti-smoking groups have conducted a long-running campaign to link smoking to lung cancer in a causal relationship. This relationship was finally proved in the British Doctors Study that ran from 1951-2001.

Which is not a factor that contributed to this causal link being proven?

  • High response rates from patients were seen in the study.

  • Epidemiological data was gathered over a long period of time.

  • Many confounding variables were taken into account and then eliminated. 

  • Many experiments were carried out to increase the experimental data available.

Did this page help you?

5
Sme Calculator
1 mark

Some of the effects of smoking are given below. 

  1. Alveolar walls become less elastic.
  2. Increased nerve impulse transmission occurs in parts of the brain.
  3. Heart rate increases.
  4. The risk of changes to genes involved in controlling the cell cycle increases.

Which row of the table contains the smoking-related causes of effects 1-4? Note that 'tar' in this context is a term used for the combination of insoluble and viscous chemicals found in tobacco smoke. 

  1. 2. 3. 4.
A. Increased activity of phagocytes Increased activity of phagocytes Nicotine in tobacco binds to acetylcholine receptors Stimulation of the glands that secrete epinephrine/adrenaline
B. Stimulation of the glands that secrete epinephrine/adrenaline Inhalation of tar Stimulation of the glands that secrete epinephrine/adrenaline Increased activity of phagocytes
C. Increased activity of phagocytes Nicotine in tobacco binds to acetylcholine receptors Stimulation of the glands that secrete epinephrine/adrenaline Inhalation of tar
D. Inhalation of tar Inhalation of tar Nicotine in tobacco binds to acetylcholine receptors Stimulation of the glands that secrete epinephrine/adrenaline

Did this page help you?

11 mark

An alveolus has several features to allow efficient gas exchange.

7xBrVPfx_1

 

Which row of the table below matches each feature of gas exchange to the correct label on the alveolus?

  I II II
A High concentration of oxygen to maintain a steep concentration gradient One cell thick for short diffusion distance Allows gases to dissolve to aid diffusion
B High concentration of carbon dioxide to maintain steep concentration gradient Allows gases to dissolve to aid diffusion One cell thick for short diffusion distance
C One cell thick for short diffusion distance High concentration of oxygen to reduce the concentration gradient Allows gases to dissolve to aid diffusion
D Allows gases to dissolve to aid diffusion Allows gases to dissolve to aid diffusion High concentration of oxygen to maintain a steep concentration gradient

Did this page help you?

21 mark

What is the function of pulmonary surfactant?

  • To increase surface tension on the alveolar walli.

  • To reduce the diffusion distance across the alveolar wall.

  • To stop the alveoli sacs from sticking together.

  • To trap microorganisms and prevent infection.

Did this page help you?

31 mark

A scientist examines a cross section of the wall of a bronchus under an electron microscope. Which of the following would be observed?

  1. Smooth muscle.
  2. Cartilage cells.
  3. Ciliated cells.
  • I and II.

  • I and III.

  • II and III.

  • I, II and III.

Did this page help you?

41 mark

Which row of the table correctly describes a bronchiole?

  Diameter / mm Collagen and elastic fibres? Site of gas exchange? Presence of cilia?
A 0.25 no yes yes
B 0.5 no no no
C 1 yes no yes
D 20 yes no yes

 

Did this page help you?

51 mark

Which set of conditions is required to allow the intake of air into the lungs during ventilation?

  • Contracted diaphragm, increased volume and increased pressure inside the thorax.

  • Relaxed diaphragm, increased volume and decreased pressure inside the thorax.

  • Relaxed diaphragm, decreased volume and increased pressure inside the thorax.

  • Contracted diaphragm, increased volume and decreased pressure inside the thorax.

Did this page help you?

61 mark

What is an example of a pair of antagonistic muscles?

  • Internal intercostal muscles and diaphragm.

  • Diaphragm and abdominal muscles.

  • Abdominal and internal intercostal muscles.

  • Diaphragm and external intercostal muscles.

Did this page help you?

71 mark

Why is it difficult to show a causal link between a risk factor and a particular disease?

  • Confounding factors influence the results making the results unreliable.

  • Epidemiological studies rely on large numbers of volunteers who suffer from the exact disease being studied to provide valid data.

  • Statistical analysis cannot be carried out on results of epidemiological studies.

  • There are ethical issues with publishing data from epidemiological studies.

Did this page help you?

81 mark

What is the correct sequence of events for the development of emphysema in the lungs?

  1. Phagocytes release elastase to destroy bacteria trapped in lungs.
  2. Alveolar walls break down.
  3. Oxygen cannot diffuse into the blood quickly enough to sustain activity.
  4. Elastase breaks down elastin reducing elasticity of the alveoli.
  5. Alpha 1-antitrypsin cannot counteract high levels of elastase.

 

 

first

last

A

I

V

IV

II

III

B

III

II

IV

I

V

C

II

IV

I

V

III

D

I

III

V

II

IV

Did this page help you?

91 mark

What conclusions can be drawn from the data in the graph?

 dUdBbl7r_2

  • There is a causal relationship between smoking and deaths from lung cancer.

  • There is a positive correlation between cigarette smoking and risk of deaths from lung cancer.

  • Women are more likely to develop lung cancer as a result of smoking than men.

  • Non-smokers are not at risk of lung cancer.

Did this page help you?

101 mark

The diagram shows a trace recorded from a spirometer.

5ktomJeq_4Which label represents the tidal volume?

 

Did this page help you?