PAG10: INVESTIGATION USING DATA LOGGER OR COMPUTER MODELLING

Describe how a spirometer is used to measure breathing. (7)

1. A person breathes through a tube connected to the oxygen chamber.

2. As the person breathes in and out, the lid of the chamber moves up and down.

3. A pen attached to the lid records the movements on a rotating drum, creating a spirometer trace.

4. The spirometer can be connected to a motion sensor, which converts movements into electronic signals recorded by a data logger.

5. The person must wear a nose clip and the machine must be airtight to ensure accurate readings.

6. An upwards slope on the trace shows the person breathing out, as volume in the chamber increases.

7. A downwards slope on the trace shows the person breathing in, as volume in the chamber decreases.

What are data loggers used for? (1)

Allow for quick & efficient gathering of data.

What are the advantages of using data loggers? (7)

- Reduces percentage error.

- Greater degree of precision.

- Not subjective.

- Time intervals can be more frequent.

- Readings can be continually taken over long periods.

- Initial start time can be delayed.

- Results can be stored for later use.

What are the disadvantages of using data loggers? (3)

- Expensive to buy the equipment.

- Sensors must be carefully calibrated.

- Faults may go unnoticed.

What is computer modelling used for? (3)

- Analyse protein structure (e.g. creating 3D images to visualise amino acid interactions).

- Observe the structure of nucleic acids at the molecular level.

- Study theoretical impacts on populations.

What population studies can be done using computer modelling? (3)

- Transmission of infectious diseases.

- Natural selection.

- Succession.