The control and coordination in plants is done by plant hormones. The plant hormones coordinate the activities of the plant by controlling one or the other aspect of the growth of the plant. So, the plant hormones are also known as plant growth substances. The growth of a plant can be divided into three stages : cell division, cell enlargement and cell di5erentiation (or cell specialisation), and these stages have particular locations in a plant. These three stages of plant growth as well as promotion of dormancy, breaking of dormancy, stomata control, falling of leaves, fruit growth, ripening of fruits and ageing in plants are controlled by the various plant hormones.
1. By which hormone the control and coordination of plants done?
(i) Photohormones
(ii) Phytohormones
2. Which hormone promotes cell division?
(i) Auxins
(ii) Gibberellins
(iii) Cytokinins
(iv) Abscisic acid
3. Which hormone promotes cell the dormancy in seeds and buds?
(i) Auxins
(ii) Gibberellins
(iii) Cytokinins
(iv) Abscisic acid
4. Do Cytokinins delay the ageing of leaves?
(i) Yes
(ii) No
5. Which hormone promotes the wilting and falling of leaves?
(i) Auxins
(ii) Gibberellins
(iii) Cytokinins
(iv) Abscisic acid
