lungs2

Question 1

How is diffusion calculated? (1)

Answer 1

length of diffusion pathway

Question 2

What is pulmonary tuberculosis caused by? (1)

Answer 2

One of two species of rod-shaped bacteria: mycobacterium tuberculosis or mycobacterium bovis

Question 3

What are the symptoms of pulmonary tuberculosis? (4)

Answer 3

Persistent cough;
Tiredness;
Weight loss;
Fever

Question 4

How is pulmonary tuberculosis transmitted? (3)

Answer 4

The bacteria is transmitted through the air by droplets released when infected people cough, sneeze, talk etc and inhaled;
Takes close contact with an infected person over a period of time rather than a short encounter;
Also transmitted through milk

Question 5

Who are at greater risk of contracting pulmonary tuberculosis? (4)

Answer 5

Those in close contact with infected individuals over long time periods;
Long-term care facilities e.g. hospitals, care homes, prisons;
Those with reduced immunity;
The very young and very old

Question 6

How should tuberculosis be prevented? (3)

Answer 6

By a vaccination containing a weakened strain of mycobacterium bovis;
Better education about TB;
Better nutrition to ensure good immune systems

Question 7

Why are the bacteria in the tuberculosis vaccine weakened before they are injected? (1)

Answer 7

So they are less likely to cause the symptoms of tuberculosis

Question 8

Describe two adaptations of the structure of alveoli for efficient gas exchange. (2)

Answer 8

Thin walls;

Total surface area is large

Question 9

Name the process by which oxygen passes from an alveolus in the lungs into the blood. (1)

Answer 9

Diffusion

Question 10

People who have been fire-breathers for many years often find they cannot breathe out properly. Explain why. (2)

Answer 10

Fibrosis reduces elasticity of alveoli;

Due to scar tissue