Question

Given below are the figures showing some kinds of tropic movements in plants. Study the same and answer the following questions:

1. Which one of these figures is correct? Give reason in support of your answer.
2. Name the kinds of movements shown by the root system and shoot system. Define each.
3. What are the two stimuli which affect root system and shoot system positively? Name them.
4. Which of the following stimuli affects the growth of the root strongly?
   1. Gravity
   2. Water
5. Draw a neat and labelled diagram of the longitudinal section of a pistil showing chemotropism in an angiospermic plant.

Answer 1

1. Figure A is correct, as it shows roots growing towards gravity and shoots growing away from gravity.
2. The root shows positive geotropism and the shoot shows negative geotropism.
   Positive geotropism is defined as the movement of a plant towards the earth's gravity. For example, roots show positive geotropism.
   Negative geotropism is defined as the movement of a plant away from gravity. For example, a shoot shows negative geotropism.
3. The shoot system responds positively to light, while the root system responds positively to the stimulus of gravity.
4. Gravity provides a more significant influence on the growth of roots, as plants require an abundance of water.
5.