Free Tropic responses questions for IGCSE Biology (0610), part of Coordination & response. Each question has the answer and the marking points an examiner would look for.
Generate a full Tropic Responses worksheet →All Coordination & response questionsA shoot is lit from one side.
Which row explains the response?
| auxin moves to | cells there | shoot bends | |
|---|---|---|---|
| A | the shaded side | elongate less | away from the light |
| B | the lit side | elongate less | towards the light |
| C | the shaded side | elongate more | towards the light |
| D | the lit side | elongate more | towards the light |
Answer: C
Where is auxin made in a shoot?
Answer: B
Which statement describes phototropism?
Answer: C
Plant shoots grow towards light.
Name this response.
Explain the role of auxin in this response.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | positive phototropism (positive) phototropism B1 | 1 |
| (b) | auxin moves to shaded side; cells elongate more auxin is made in the shoot tip B1 it moves to the shaded side B1 it stimulates cell elongation there, so the shoot bends towards the light B1 | 3 |
Roots grow downwards and shoots grow upwards.
Name the response of roots to gravity.
Explain the advantage of this response for the plant.
Describe an experiment to show that shoots respond to light.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | positive gravitropism positive gravitropism B1 | 1 |
| (b) | roots reach water and anchor roots grow towards water and minerals in the soil B1 and anchor the plant B1 | 2 |
| (c) | seedlings with one-sided light vs control grow seedlings with light from one side and a control in uniform light/clinostat B1 observe direction of growth after a few days B1 | 2 |
A student investigates the response of oat seedlings to light coming from one side.
Name the response of a shoot to light, and state whether it is positive or negative.
Explain how auxin causes the shoot to bend towards the light.
The tips of some seedlings are covered with foil caps. Predict how these seedlings grow and explain why.
Explain the advantage to a plant of positive phototropism.
A seedling is placed on its side in the dark. Describe how the root and shoot respond, and name this response.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | phototropism; positive phototropism B1 positive (grows towards light) B1 | 2 |
| (b) | auxin made in tip; moves to shaded side; stimulates cell elongation there; shaded side grows faster, shoot bends towards light auxin is produced in the shoot tip B1 auxin moves / diffuses to the shaded side B1 auxin stimulates cell elongation B1 cells on the shaded side elongate more so the shoot bends towards the light B1 | 4 |
| (c) | grow straight up; tip cannot detect the direction of light grow straight up / no bending B1 the tip (which detects light) is covered so auxin is evenly distributed B1 | 2 |
| (d) | more light absorbed; more photosynthesis leaves receive more light B1 so more photosynthesis / more glucose for growth B1 | 2 |
| (e) | gravitropism; root grows down; shoot grows up gravitropism B1 root grows downwards (positive) B1 shoot grows upwards (negative) B1 | 3 |
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in