Question

Repairment of damaged tissue by cell division is
(a) Epimorphosis regeneration
(b) Morphallaxis regeneration
(c) Exponential growth
(d) Deacceleration growth

Answer 1

In an organism, if a specific organ or tissue is damaged or regenerated. Regeneration of the whole part or repair of that particular damaged tissue takes place by a process which is seen in amphibians like salamanders.

Complete answer:
Regeneration of an organism’s specific part by the extensive proliferation of somatic cells, differentiation, reformation, and formation of the blastema is called epimorphosis regeneration. It is a simple model for the development as it occurs only at the site of infection and surroundings rather than occurring in the whole system. The anatomy of the organism and the original polarity that is present before the damage is retained by this process. It is observed in invertebrates as well as vertebrates. Examples: amphibians, planarians, etc.

Additional Information:
- In the vertebrates to proliferate cells into new tissues, epimorphosis depends on blastema formation.
- Migration of epidermal cells at wound margins forms wound epidermis. Matrix metalloproteinases are secreted by mesenchymal tissues which thicken the wound epithelium forms an apical ectodermal cap.
- Nerves at the site of the limb are degraded due to apical ectodermal cap. It causes the progress zone to re-establish.
- Cells differentiate and become separated. Mesenchymal cells form blastema under the presence of apical ectodermal caps.
Fibrinoblasert growth cells are also released by apical ectodermal cells which help in the development of new limbs.
So, the correct answer is ‘epimorphosis regeneration’.

Note:
-Cartilage is formed only from cartilage cells and muscle tissue is formed only from muscle cells. Their original specification is retained even after the differentiation.
-In an organism, if a specific tissue is lost or degenerate. Regeneration of that specific tissue is called morphallaxis regeneration.