Question

Define the term Quiescence and Dormancy.

Answer 1

The temporary state of a cell during which its division is restricted but maintains the capability of re-entering into the cell proliferations is called a quiescent state. But in case of dormancy, almost all phases including cell growth, development and progression are stopped.

Complete answer:
Generally, quiescence is found as a reversible phase in a cell during a cell cycle. In this phase the cell losses the ability of further division but can possibly move into cell proliferation. It has been found that the few of the mature stem cells are retained in a quiescent state and could further get activated when triggered, for instance due to some type of tissue injury. During quiescence state the cells usually rest for a particular period till they get activated or triggered. The quiescent seeds grow significantly in the favorable and suitable environmental conditions like sufficient water, regular atmospheric conditions and physiologically optimum temperature, while the dormant seeds necessitate some additional circumstances like specified environmental conditions, physical factors, hormonal, and/or others to activate germination. Basically, two types of seed dormancy have been reported including physical (seed coat) dormancy and internal dormancy. In physical type of dormancy, the permeation of water and/or oxygen is prevented by the seed coats of plants. Several times dormancy is caused by restraining the chemicals within the seed. During dormancy state, the metabolic activities are reduced and thus it assists an organism to preserve energy.

Note: In broader view, quiescence appears due to nutritional lack and progression conditions while senescence state is occurred because of aging and severe damages to DNA (Deoxyribose nucleic acid). Dissimilar to the quiescence state, the senescence state is a degenerative process that can lead to definite cell death.