CBSE Class 10 Science 2023 · Paper 31/4/3 · Question 21
Name a plant hormone responsible for bending of a shoot of a plant when it is exposed to unidirectional light. How does it promote phototropism ?
Answer
Auxin gathers on the shaded side, making its cells grow longer, so the shoot bends towards the light.
The hormone is auxin. It is synthesised at the tip of the shoot and helps the cells to grow longer. When light falls on the shoot from one side, auxin diffuses towards the shaded side, so its concentration there becomes higher. The cells on the shaded side therefore grow longer than those on the lit side, and the shoot bends towards the light: this is positive phototropism.
🔒 Step-by-step solution
Sign up free to see every step of how it is worked out.
From the board paper
More questions from Control and Coordination
Class 10 Science — every question with an expert-verified, step-by-step solution.
- Q1 Which of the following is a plant hormone?
- Q1 What is the difference between a reflex action and walking?
- Q2 The gap between two neurons is called a
- Q2 What happens at the synapse between two neurons?
- Q3 The brain is responsible for
- Q3 Which part of the brain maintains posture and equilibrium of th…
- Q4 What is the function of receptors in our body? Think of situations…
- Q4 How do we detect the smell of an agarbatti (incense stick)?
- Q5 Draw the structure of a neuron and explain its function.
- Q5 What is the role of the brain in reflex action?
- Q6 How does phototropism occur in plants?
- Q7 Which signals will get disrupted in case of a spinal cord injury?
All 286 questions on Control and Coordination → Browse all Science chapters →