Question

regeneration that occurs in hydra and planaria is caused by​

Answer 1

hydra perform regeneration but reproduce by the method of budding. The hydra and the planarian flatworm have long served as model organisms for their highly adaptive regenerative capabilities. Once wounded, their cells become activated and restore the organs back to their pre-existing state.

Answer 2

Answer:

For example, hydra perform regeneration but reproduce  by the method of budding. The hydra and the planarian flatworm have long served as model organisms for their highly adaptive regenerative capabilities. Once wounded, their cells become activated and restore the organs back to their pre-existing state

Regeneration in Hydra is polarized and does not depend on growth. When cut in two,  the lower piece will develop a head & the upper will develop a foot. A piece excised from the Hydra body will regenerate both a head and a basal disc in the same polarity