Micro-propagation is

1. propagation of microbes in vitro

2. propagation of plants in vitro

3. propagation of cells in vitro

4. growing plants on smaller scale

(b) Micro-propagation is propagation of plants in vitro to achieve a large number of plants in very short durations. This results in genetically identical plants and is widely used in forestry and floriculture.
Page 177, XII NCERT