• Mitosis is the type of cell division that produces new cells for growth and to replace old cells that are worn out, damaged or dead. An application of

mitosis is in cloning and tissue culture.

• Tissue culture is the growth of tissues or cells separate from the organism. This is typically facilitated via use of a liquid, semi-solid, or solid growth media, such as broth or agar. Tissue culture commonly refers to the culture of animal cells and tissues, while the more specific term plant tissue culture is used for plants.

• Plant tissue culture is a practice used to propagate plants under sterile conditions, often to produce clones of a plant.

• Nature has been cloning organisms for billions of years. For example, when a strawberry plant sends out a runner (a form of modified stem), a new plant grows where the runner takes root. That new plant is a clone. Similar cloning occurs in grass, potatoes and onions.

ORIGIN OF PLANT TISSUE CULTURE

• Scientists have been able to clone plants by taking pieces of specialized roots, breaking them up into root cells and growing the root cells in a nutrient-rich culture. In culture, the specialized cells form calluses(undifferentiated mass of tissue). The calluses can then be stimulated with the appropriate plant hormones to grow into new plants that are identical to the original plant.

DIAGRAM AND CHARTS OF PLANT TISSUE CULTURE