Practise 38 exam-style questions on Principles of organisation for AQA GCSE Biology. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
38 questions
1–4 marks each
Instant marking
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20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
2 marks
Why are tissues composed of many cells rather than one large cell? Give two reasons related to function or exchange.
Model answer
Many cells give a larger surface-area-to-volume ratio for exchange (diffusion), and allows specialised cells to perform different roles and avoid limitations of large cell transport distances.
Explanation
Smaller cells mean more surface area relative to volume for exchange and shorter internal diffusion distances, and groups of cells allow division of labour and specialisation.
Mark scheme
1 mark
larger surface-area-to-volume ratio (more efficient exchange/diffusion)
1 mark
specialisation / reduced transport distance within each cell (allows efficient function)
Allow easier control/repair/communication.
Question 2
3 marks
A tubular organ is formed from three layers: an inner epithelial layer, a middle muscle layer and an outer connective layer. Explain how the combination of these tissues enables the organ to function.
Model answer
The epithelium provides a protective and absorptive lining; the muscle layer allows the organ to change shape or move contents (peristalsis/contraction); connective tissue provides support and contains blood vessels for supply.
Explanation
Organs integrate tissue functions: epithelium interfaces with contents, muscle generates movement, and connective tissues support and nourish other layers.
Mark scheme
1 mark
epithelial lining for protection / absorption / secretion
1 mark
muscle layer for movement / contraction (e.g. peristalsis / changing shape)
1 mark
connective tissue for support and supply (blood vessels, nerves)
Question 3
3 marks
A sample of organ X contains many cells that are dead and lignified. Predict the organ and explain the advantages of these cell features.
Model answer
Likely xylem tissue in a plant organ (e.g. stem/wood). Dead, lignified cells form hollow tubes for efficient water transport and provide mechanical support/rigidity.
Explanation
Xylem vessels are dead and lignified to create durable, hollow conduits for moving water and to support the plant structurally.
Mark scheme
1 mark
xylem (or plant stem/wood/xylem tissue)
1 mark
dead, lignified cells form hollow tubes for water transport
1 mark
lignin gives strength/support / rigidity
Question 4
4 marks
Describe an experiment to compare the thickness of two tissues using a light microscope, including how to make measurements and a control to ensure valid comparison.
Model answer
Prepare similar thin transverse sections of both tissues, mount and focus under same magnification. Use an eyepiece graticule calibrated with a stage micrometer to measure thickness; take multiple measurements and calculate means. Ensure same magnification, staining and sectioning procedure as controls.
Explanation
Standardised sample preparation and calibrated measurement allow accurate thickness comparison; multiple replicates reduce measurement error.
Mark scheme
1 mark
prepare similar thin sections and mount on slides
1 mark
use same magnification for both and same staining / method
This is the control to ensure validity.
1 mark
measure with eyepiece graticule calibrated by stage micrometer (or use scale bar)
1 mark
take multiple measurements and calculate mean for each tissue
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