A student observes a seedling growing in a pot. Over several days, the seedling grows taller, produces new leaves, and responds to the direction of light by bending towards it. Explain how these observations demonstrate three characteristics of living organisms, and state one additional characteristic not shown by these observations.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A seedling is kept on a windowsill. Over five days, it increases in height, produces two new leaves, and its shoot bends towards the window.
Model answer (4 marks)
Growth – the seedling increases in height and produces new leaves, showing that living organisms grow by increasing cell number or size.
Sensitivity – the shoot bends towards the light, demonstrating that living organisms can detect and respond to external stimuli.
Nutrition – the seedling uses water, carbon dioxide and light energy to carry out photosynthesis, producing food and energy for growth.
Additional characteristic – respiration (the seedling releases oxygen and consumes carbon dioxide).
Sensitivity – the shoot bends towards the light, demonstrating that living organisms can detect and respond to external stimuli.
Nutrition – the seedling uses water, carbon dioxide and light energy to carry out photosynthesis, producing food and energy for growth.
Additional characteristic – respiration (the seedling releases oxygen and consumes carbon dioxide).
Examiner tips
- Use the exact terms ‘growth’, ‘sensitivity’, and ‘nutrition/ photosynthesis’ as the mark scheme recognises.
- Show each characteristic with a separate sentence and give a clear example from the observation.
- Remember to state one extra characteristic that wasn’t shown, e.g. respiration.
- Keep the answer concise – 4–5 sentences is enough for full marks.
Common mistakes
- Mixing up the order of the characteristics or using vague phrases like ‘the plant is alive’ instead of the specific traits.
- Failing to mention the extra characteristic or giving a non‑living trait such as ‘colour’.
- Using UK spelling inconsistently (e.g., ‘colour’ instead of ‘color’).
Mark scheme (4 marks)
- Growth — the seedling increases in size / height / produces new leaves, showing that living organisms grow (by increasing in cell number or cell size)
- Sensitivity / response to stimuli — the shoot bends towards the light, showing the seedling detects and responds to an external stimulus (light)
- Nutrition / photosynthesis — the seedling takes in / uses materials from the environment (water, carbon dioxide, light energy) to make food / carry out photosynthesis, providing energy for growth
- Any one additional characteristic of living organisms correctly stated: respiration / excretion / reproduction / movement
Related
- All Pearson Edexcel International GCSE Biology (4BI1) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →