What is the example of Epimorphosis?
(A) Limb regeneration in amphibians is a representative example of epimorphosis. In this type of regeneration, a mass of undifferentiated cells referred to as the ‘blastema’ is initially formed after wound healing and then blastema cells actively proliferate to restore the lost part of the amputated organ.
What is Morphallaxis and Epimorphosis?
Morphallaxis is the regeneration of specific tissue in a variety of organisms due to loss or death of the existing tissue. The word comes from the Greek allazein, (αλλάζειν) which means to change. Epimorphosis is the regeneration of a part of an organism by proliferation at the cut surface.
What are eyespots in planaria?
Planarians have ocelli (eyespots) allow the presence and intensity of light to be determined. These structures are covered but have an opening to one side and forward. They can tell the direction of light because shadows fall on some of the receptor cells while others are illuminated. They move away from light.
What is mesenchyme in planaria?
The mesenchyme of the planarian body is populated with numerous undifferentiated pluripotent cells, known as neoblasts. The capacity of this cell type to self-renew, rapidly proliferate, and migrate to sites of injury gives planarians the unmatched ability to regenerate.
What is meant by Epimorphosis?
Epimorphosis is defined as the regeneration of a specific part of an organism in a way that involves extensive cell proliferation of somatic stem cells, dedifferentiation, and reformation, as well as blastema formation.
What’s the function of planarian?
Because of their remarkable ability to regenerate lost parts, planarians are often used experimentally to study the process of regeneration. In the flatworm Planaria, the brain consists of two cerebral ganglia (clusters of nerve cells) from which nerve cords extend the length of the body.
What type of cells are contained in the blastema?
The creatures heal so well because the muscle, bone and skin cells nearest to the amputation site revert into a more generic form, forming a clump of adult stem cells called a blastema. These cells then divide and differentiate into the tissue types needed to make a new limb.
How does the planaria worm go through epimorphosis?
Planaria begin epimorphosis by the epidermis contracting immediately after the worm is cut at the head as a predator reactionary mechanism in order to decrease the surface area at the site of the cut.
How are planarians related to tapeworms and flukes?
Planarians belong to the flatworm phylum, or the phylum Platyhelminthes. The name of the phylum comes from the Greek words platy, which means flat, and helminth, which means worm. Tapeworms and flukes are also flatworms.
Is the PIWI gene involved in planarian regeneration?
One planarian stem cell gene that’s believed to be involved in regeneration is called the piwi (pronounced pee-wee) gene. We have a closely-related gene in our sperm and eggs and in some of our stem cells. Some of the other genes involved in planarian regeneration also resemble ones in humans.
What do you need to know about epimorphosis?
Epimorphosis is defined as the regeneration of a specific part of an organism in a way that involves extensive cell proliferation of somatic stem cells, dedifferentiation, and reformation, as well as blastema formation.