Explain the process of phototropism in plants, including the roles of light and auxin, and predict the shoot's growth in scenarios P, Q, and R.

Here are the answers to the remaining questions:

12. a) i)

• P: The shoot will bend towards the light source.
• Q: The shoot will grow straight upwards.
• R: The shoot will bend towards the light source.

a) ii)
Phototropism is the growth of a plant towards a light source, primarily controlled by the hormone auxin produced in the shoot tip. Unilateral light causes auxin to migrate to the shaded side of the shoot, promoting cell elongation there and causing the shoot to bend towards the light.

• In P and R, the shoot tip is exposed to unilateral light, allowing auxin redistribution and bending.
• In Q, the shoot tip is covered by a