- Created by: cathy
- Created on: 04-02-13 19:09
The growth and development of many plants are regulated by the activity of plant hormones. Hormones are biochemical substances produced in one part of a plant and transported to a different part where they exert a particular effect.
An example of a plant hormone is a series of substances called auxins. Auxins increase the length of most plant cells and thereby contribute to the growth and elongation of the plant.
Another plant hormone is abscisic acid, which is produced in mature leaves and inhibits growth in developing leaves and germinating seeds. The inhibition occurs during the winter, contributing to the plant's dormancy. Another hormone,ethylene, encourages ripening and the dropping of leaves and fruits from the trees. Slight pressure permits the…