What Is Meant By Dormancy And Germination Of Seeds? Can You Describe The Changes During Germination?

This is another one of those biology questions related to the chapter of plants. The first step in germination is the absorption of water by the seed. The seed swells and the testa becomes more permeable to oxygen and carbon dioxide. The swelling of the seed may rupture the testa.  

The ripe seeds of plants germinate when they are exposed to favorable environmental conditions. However, the seeds of many plants do not germinate as soon as they are shed. They have to pass through a "resting" or dormant period during which they will not germinate no matter how favorable the environmental conditions are. The dormant period may be days, weeks or sometimes even years, depending on the species. Dormant seeds are usually dry; their vital activities are much reduced and they respire anaerobically. They are able to withstand adverse external conditions such as cold or very dry weather. Thus dormancy enables seeds to tide over unfavorable seasons such as winter or drought in the tropics.

If seeds are kept dry their dormant period can be prolonged. When the dormant period is over, the seeds will sprout if conditions are favorable. However, many seeds lose their viability if kept more than a few weeks in the tropics.