Tag: reproduction in animals

A. Epimorphosis - Regeneration of limbs or tail is an epimorphosis regeneration. Replacement of lost organ of the body by proliferating new cells from the surface of the injured part is called Epimorphosis.

B. Reparative regeneration - Regeneration of damaged cells or tissues in the injured parts, in multicellular organisms is called reparative regeneration.

C. Metamorphosis - the process of transformation from an immature form to an adult form in two or more distinct stages.

D. Morphogenesis - the biological process that causes an organism to develop its shape.

So, the correct option is ‘Reparative regeneration’.

Regeneration is the process by which certain organisms can replace or restore their lost or amputated body parts. Different organisms have different ability to regenerate their body parts. There are certain organisms such as starfish, crayfish, many reptiles and amphibians which exhibit remarkable tissue regeneration. For example, deer can regrow their antlers, lizards can regrow their tails and starfishes can regrow their limbs. Lizards discard their tails as a result of defense mechanism and can regrow it within 60 days. 

Regeneration is the process of renewal, restoration and growth that makes genomes, cells , organisms and ecosystems.
While reproduction is the biological process by which new individual organism, i.e., offspring are produced form their parents.
Thus, the correct answer is option (B), 'False'.

Planaria belongs to the phylum Platyhelminthes.

Many animals can regenerate, that is, regrow or grow new parts of their bodies to replace those that have been damaged. Echinoderms can regenerate missing limbs, arms, spines and even intestines (for example sea cucumbers). Some brittle stars and sea stars can reproduce asexually by breaking a ray or arm or by deliberately splitting the body in half. Each half then becomes a whole new animal. Planarians are flatworms when cut into pieces, each piece can grow into a new worm. Sea cucumbers have bodies that can grow to be three feet long and shows the phenomena of regeneration. Spiders can regrow missing legs or parts of legs. Sponges can be divided. The cells of the sponge will regrow and combine exactly as before. Starfish that lose arms can grow new ones, sometimes an entire animal can grow from a single lost arm. Birds (Aves) on the other hand, do not have this ability

The spontaneous removal or casting off of a body part, especially when the organism is injured or under attack is autotomy or self ampulation. It is recorded in loss legs in crabs, loss of tails in lizards, loss of viscera in Holothurian echinoderms.

So, the correct option is ‘All the above’.

The reconstruction of an entire animal from a small fragment by reorganizing the existing cells, is called Morphallaxis. The regenerated animal is far smaller than the original one after the completion of the process. It grows to attain the normal size. It is reported in Porifers, Coelenterates, flatworms, Nemarteans, and some ascidians.

So, the correct option is ‘Porifers, Coelenterates, flatworms, Nemarteans, and some ascidians’.