Tropic responses — Paper 2 · IGCSE Biology (9-1) 0970

26 A seedling was placed in a horizontal position. Which diagram shows the result of the gravitropic responses in the seedling? A B root root shoot shoot C D shoot root root shoot

1 marks

Answer: C

This question in 0970/21 May/June 2018

24 A student used two seedlings X and Y to investigate phototropism. The diagram shows their investigation. light light piece of glass piece of glass X X at the start of after some time the experiment no curvature towards light light light piece of glass piece of glass Y Y at the start of after some time the experiment gives curvature towards light Which statement explains the difference in results between X and Y? A The piece of glass destroyed the auxin on the shaded side of the seedling. B The piece of glass destroyed the auxin on the side of the seedling facing the light. C The piece of glass in X stopped the auxin travelling down the shaded side of the seedling. D The piece of glass in X stopped the auxin travelling down the side of the seedling facing the light.

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2018

27 Three plant shoots have their tips removed. Two of the shoots have a piece of agar gel placed on them, as shown in the diagram. The agar gel contains auxin. The shoots are exposed to light coming from one direction. agar gel containing auxin light plant plant plant shoot shoot shoot What is the appearance of the shoots after two days? A B C D

1 marks

Answer: A

This question in 0970/22 May/June 2019

24 The diagram shows the shoot and root of a seedling responding to gravity. Which row shows where the auxin accumulates and the effect of this in the shoot? accumulates effect A lower surface inhibits cell elongation B lower surface promotes cell elongation C upper surface inhibits cell division D upper surface promotes cell division

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2019

1 The diagram shows what happened in an experiment with plant seedlings. start next day light light Which characteristic of living things made the seedlings grow towards the light? A excretion B nutrition C respiration D sensitivity

1 marks

Answer: D

This question in 0970/22 May/June 2020

28 Which statements about auxin are correct? 1 Auxin is made in all cells in plants. 2 Auxin causes cells to elongate. 3 Auxin moves between the cells by osmosis. 4 Auxin is unequally distributed. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: D

This question in 0970/21 May/June 2021

28 The diagram shows a plant next to a window. light Which statement explains the plant shoot’s growth? A There is a higher concentration of auxin in the cells on the shaded side of the shoot. This prevents cell elongation. B There is a higher concentration of auxin in the cells on the shaded side of the shoot. This stimulates cell elongation. C There is a lower concentration of auxin in the cells on the shaded side of the shoot. This prevents cell elongation. D There is a lower concentration of auxin in the cells on the shaded side of the shoot. This stimulates cell elongation.

1 marks

Answer: B

This question in 0970/22 May/June 2021

28 A seed is placed and grown on a rotating disc, as shown. seed pinned to the constantly rotating disc Which diagram shows the appearance of the seedling shoot after seven days? A B C D

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2021

26 An experiment was set up to investigate the growth of shoots in different conditions, as shown. shoot tip removed foil cap direction of light Which diagram shows the results that would be seen a few days later? A B C D

1 marks

Answer: D

This question in 0970/21 May/June 2022

26 A young maize seedling is grown from a seed. The seedling is placed on its side and left in a room with a light source for several days. direction of light root shoot What will happen to the young shoot? A Auxin becomes concentrated in the lower part of the shoot and the shoot grows towards the light. B Auxin becomes concentrated in the upper part of the shoot and the shoot grows towards the light. C Auxin is evenly distributed in the shoot and the shoot grows towards the light. D Auxin is evenly distributed in the shoot and the shoot grows away from the light.

1 marks

Answer: A

This question in 0970/22 May/June 2022

26 Which row about tropic responses is correct? gravitropism phototropism A root grows away from gravity shoot grows away from light source B root grows away from gravity shoot grows towards light source C root grows towards gravity shoot grows away from light source D root grows towards gravity shoot grows towards light source

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2022

26 What is a correct statement about auxin in shoots? A It is made only on the shaded side of the shoot. B It is more concentrated on the side of the shoot that receives the most light. C It moves through the shoot by osmosis. D It stimulates cell elongation.

1 marks

Answer: D

This question in 0970/21 May/June 2023

26 Which distribution of auxin will cause the shoot tip to grow towards the light? A B C D key direction of light auxin

1 marks

Answer: D

This question in 0970/22 May/June 2023

25 What is an example of phototropism? A the growth of a root in the direction of gravity B the growth of a shoot towards light C the release of energy from glucose using light D the synthesis of glucose using light

1 marks

Answer: B

This question in 0970/21 May/June 2025

26 A young seedling is growing underground. The shoot grows towards the surface of the ground. The root grows away from the surface of the ground. Which row describes the responses involved? gravitropism phototropism root shoot root shoot A yes yes no no B yes no no yes C no yes yes no D no no yes yes

1 marks

Answer: A

This question in 0970/22 May/June 2025

21 The diagram shows an experiment using two wheat shoot tips, X and Y. after two days in even light shoot tip removed X Y X Y Which statement is supported by the evidence provided by this experiment? A Auxin moves through the plant by osmosis. B Auxin is made in the shoot tip. C Auxin is unequally distributed in response to light. D Auxin inhibits cell elongation.

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2025