(i) The two modes of asexual reproduction observed in hydra are:

1. Regeneration: Many fully differentiated organisms have the ability to give rise to new individual organisms from their body parts. That is, if the individual is somehow cut or broken up into many pieces, many of these pieces grow into separate individuals. For example, simple animals like Hydra and Planaria can be cut into any number of pieces and each piece grows into a complete organism. This is known as regeneration. Regeneration is carried out by specialised cells. These cells proliferate and make large numbers of cells.
2. Budding: Organisms such as Hydra use regenerative cells for reproduction in the process of budding. In Hydra, a bud develops as an outgrowth due to repeated cell division at one specific site. These buds develop into tiny individuals and when fully mature, detach from the parent body and become new independent individuals.
(ii) There are many plants in which parts like the root, stem and leaves develop into new plants under appropriate conditions. Unlike in most animals, plants can indeed use such a mode for reproduction. This property of vegetative propagation is used in methods such as layering or grafting to grow many plants like sugarcane, roses, or grapes for agricultural purposes.
Vegetative propagation is practiced for growing some types of plants because of the following reasons: -
1. Plants that have lost their capability to produce seeds can be propagated by this method.
2. It helps to grow plants bearing superior traits, as they are genetically identical to the parent plant.
3. It is used for growing plants which require a longer time to grow and become mature.