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Dormancy should not be confused with seed coat dormancy, external dormancy, or hardheadedness, which is caused by the presence of a hard seed covering or seed coat that prevents water and oxygen from reaching and activating the embryo. It is a physical barrier to germination, not a true form of dormancy (Quinliven, 1971; Quinliven and Nichol ...
True dormancy or inherent (or innate) dormancy is caused by conditions within the seed that prevent germination even if the conditions are favorable. [7] Imposed dormancy is caused by the external conditions that remain unsuitable for germination [8] Seed dormancy can be divided into two major categories based on what part of the seed produces dormancy: exogenous and endogenous. [9]
Four degrees Celsius is cool enough to end dormancy for most cool dormant seeds, but some groups, especially within the family Ranunculaceae and others, need conditions cooler than -5 C. Some seeds will only germinate after hot temperatures during a forest fire which cracks their seed coats; this is a type of physical dormancy.
Ectothermic animals also undergo periods of metabolic suppression and dormancy, which in many invertebrates is referred to as diapause. Some researchers and members of the public use the term brumate to describe winter dormancy of reptiles, but the more general term hibernation is believed adequate to refer to any winter dormancy. [8]
Aestivation (Latin: aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a lowered metabolic rate, that is entered in response to high temperatures and arid conditions. [ 1 ]
Detection dormancy period Risk level P*S (+D) Actions for further investigation / evidence Mitigation / requirements 1.1.1.1: Brake manifold ref. designator 2b, channel A, o-ring: Internal leakage from channel A to B: a) O-ring compression set (creep) failure b) surface damage during assembly Landing: Decreased pressure to main brake hose
It orchestrates seasonal growth, development, reproduction, migration, and dormancy that affect survivorship and reproductive success. [14] Changes in photoperiod over days and seasons created the opportunity for the development of internal clocks and eventually create circadian and circannual rhythms. [3]
Agricultural Involution: The Processes of Ecological Change in Indonesia is one of the most famous of the early works of Clifford Geertz.Its principal thesis is that many centuries of intensifying wet-rice cultivation in Indonesia had produced greater social complexity without significant technological or political change, a process Geertz terms—"involution".