Question

15. Stem and its branches grow towards sunlight. This is (a) Positively phototropic movement (b) Positively geotropic movement (c) Negatively phototropic movement (d) Positively hydrotropic movement​

Answer 1

Answer:

(a) positively photo tropic movement

Explanation:

bcoz the branches are growing towards the light. it is phototropism

Answer 2

Stem and its branches grow towards sunlight. This is (a) Positively phototropic movement.

• Positive phototropic movement: If the stem grows towards the sunlight, it is called as positively phototropic movement.
• It is a tropic movement induced in the plant, in response to the stimuli called as light.
• Whereas, the growth of root is negatively phototropic.
• Tropic movements are of various types: In this, the plant grows in the direction of light.
• The plants have a chemical called auxin, which reacts in response to light.
• This causes the cells of the plants to elongate.
• Growth towards light is positive phototropism, while that away from the light is negative phototropism.
• In this, the response acts on the protoplasm from one side.
• A tropic movement may be towards or away from the stimulus.
• Tropic movements are of various types: In this, the plant grows in the direction of light.

• The plants have a chemical called auxin, which reacts in response to light.
• This causes the cells of the plants to elongate.