Question

(A) The type of regeneration in Hydra is known as epimorphosis.
(B) Members of reptiles such as lizards exhibit autotomy.
(C) Regeneration of limb in amphibians involves morphallaxis.
a. (A) and (B) are false but (C) is true.
b. (B) and (C) are false but (A) is true.
c. (B) and (C) are true but (A) is false.
d. (A) and (C) are true but (B) is false.
e. (A) and (C) are false but (B) is true.

Answer 1

Hint:At first we need to know the terms given in the question like ‘epimorphosis’, ‘autotomy’, and ‘morphallaxis’. Once we know the terms we can easily find out which statement is true.

Complete answer: 1. Epimorphosis: It is defined as the regeneration of a specific part of an organism in a way involving proliferation at the cut surface.
2. Morphallaxis: It is the regeneration of a part or organism from a fragment by reorganization.
3. Autotomy: It is the ability of certain animals to rebase part of the body that has been grasped by an external agent.
Eg: Tail regeneration in lizards.
But if the broken part develops into a complete organism, it is called morphallaxis which is observed in lower organisms like Hydra. Thus, the statements (A) and (C) are wrong.
Reason: Epimorphosis involves the regeneration of limbs in amphibians and the type of regeneration in Hydra is Morphallaxis and not Epimorphosis. Statement (B) is correct.
Reason: Autotomy acts as a self-defense mechanism in certain animals like lizards where they shed off a part of this body.

So, the answer is option ‘e’ which says that (A) and (C) is false but (B) is true.

Additional information:
Epimorphosis can be considered a simple model for development though, it only occurs in tissues surrounding the site of injury rather than occurring system-wide. Epimorphosis regeneration can be observed in both vertebrates and invertebrates such as the common examples: salamander, annelids, and planarians. The notable feature of Morphallaxis is that a large majority of regenerated tissue comes from already present tissue in the organism, That is, the one severed section of the hydra forms into a smaller version of the original hydra, approximately the same size as the severed section.

Note: Morphallaxis is often contrasted with epimorphosis. Although cellular differentiation is seen in both processes but in morphallaxis, there is a regeneration of the complete organism whereas in epimorphosis only the part of an organism is regenerated.