Question

Reparative regeneration involves
A) Replacement of last part
B) Growth of whole organism from fragment
C) Healing injury
D) Both a and b

Answer 1

Hint: Regeneration is referred to as a natural process which helps in restoring damage to cells or tissues, organs or entire body parts. This is of two types: Reparative regeneration, restorative regeneration. Regeneration is carried out by specialised cells. These cells form a mass of cells that undergo changes in specialised function.

Complete answer:
Regeneration is a natural process of restoration, renewal of cells, tissue growth, organs and entire body parts. This type of process occurs in both vertebrates and invertebrates. Mechanism of Regeneration has two types: morphallaxis and epimorphosis.
A) replacement of the last part: Replacement of the lost part is known as Regeneration. The organism has the power to repair or restore certain damaged cells. Organisms differ in their ability to restore the last part.
B) growth of whole organisms from fragments: Morphallaxis is a type of regeneration. This type of process occurs by the growth of organisms from a fragment. Morphallaxis is observed in hydra, where growth of new organisms is observed from fragments.
C) healing injury: It occurs in reparative regeneration. Reparative regeneration is a healing process that takes place in damaged cells or tissues that are regenerated in multicellular organisms. It is a rare phenomenon in mammals.

Thus, the correct answer is C) Healing injury.

Note:
Multicellular animals have the capacity to repair the damaged cells of the body. Reparative regeneration is a common phenomenon that occurs in vertebrates and invertebrates. Morphallaxis is the process of reconstruction of an entire animal from a small fragment. Epimorphosis is a process of replacing the last organ by new proliferating cells.