Undifferentiated cells in the meristems of plants allow indeterminate growth.
Mitosis and cell division in the shoot apex provide cells needed for extension of the stem and development of leaves.
Plant hormones control growth in the shot apex.
Plant shoots response to the environment by tropisms.
Auxin efflux pumps can set up concentration gradients of auxin in plants tissue.
Auxin influences of cell growth rates by changing the pattern of gene expression.
Applications
Micropropagation of plants using tissue from the shoot apex nutrient agar gels and growth hormones.
Use of micropropagation for rapid bulking up of new varieties, production of virus-free strains of existing varieties and propagation of orchids and other rare species.
Nature of Science
Developments in scientific research follow improvements in analysis and eduction-improvements in analytical techniques allowing the detection of trace amounts of substances has led to advances in the understanding of plant hormones and their effect on gene expression.