Budding: It is that type of asexual reproduction in which one or more unicellular or multicellular outgrowths, called buds, are formed on or inside the parental body.
 

How it Happens: Each multicellular outgrowth called bud enlarges, develops the parental characteristics and then separates to lead an independent life. It feeds, grows, becomes an adult and repeats the process.

 

Occurs in: Budding is found in sponges (Scypha), coelenterates (Hydra), annelids (Syllis) and tunicates (Salpa) among animals. Among fungi, it is found in yeasts (Fig. 8).

In Hydra (Fig. 7) and Scypha (Fig. 9) the budding is exogenous as the bud is formed on the outer surface of parental body while in Spongilla (a fresh water sponge), the budding is endogenous as a number of buds called gemmules are formed inside the parental body.

Each gemmule (Fig 10) of Spongilla is a mass of undifferentiated cells, called archaeocytes, surrounded by a protective coat of amphidisk spicules. Gemmule helps in perennation and dispersal. During favourable conditions, archaeocytes come out of gemmule through micropyle and form a new sponge.

In Scypha (Fig. 9), the exogenous buds remain attached to the parental body and may develop secondary buds to form a kind of colony.

Unlike the binary fission, the identity of the parent body is retained after reproduction.

 Differences between Binary and Multiple Fission.

	Characteristics	Binary fission	Multiple fission
1.	Number of daughters produced	Parent divides in two daughters.	Parent divides in many daughters.
2.	Time of formation	During favourable conditions.	During unfavour­able conditions.
3.	Fate of parent	Nothing is left with parent.	Residual cyto­plasm is left.