When the plant stem is above ground
Germination.
Pollen tube germination is the process by which a pollen grain, upon landing on a compatible stigma, develops a tube that extends down the style toward the ovule in the ovary. This tube carries sperm cells from the pollen grain to fertilize the ovule, leading to seed formation. The germination process involves the hydration of the pollen grain and the growth of the tube, which is guided by chemical signals from the ovule. Successful germination is crucial for plant reproduction.
Hypogeal germination is a type of seed germination where the cotyledons remain below the ground after germination. The stem elongates to bring the cotyledons and leaves above the soil surface. This type of germination is common in dicot plants.
There are three types of germination 1.Hypogeal germination and epigeal germination and Cleistogeal germination. Hypogeal Germination: In this kind of Germination, the seed leaves or the cotyledons remain under the surface of soil. example: pea seeds - Epigeal Germination: In this type of Germination, the seed leaves grow above the ground on the new shoot. example: ash tree -Cleistogeal Germination: A special leaf that has a central umbrella like stalk forms above the ground which protects the shoot from any damage. So the development of the shoot can not be seen.
germination
it is the factor when the embryo signals for water.
The end of germination is signaled by the emergence of the plant shoot above the soil surface, and the beginning of growth is marked by the development of leaves and the expansion of roots to uptake nutrients from the soil. This transition is crucial for the plant to start photosynthesis and establish itself in its environment.
Sunlight signals for germination of cress seeds
Seeds are typically triggered to germinate by a combination of factors such as water availability, temperature, and light exposure. These environmental signals activate different physiological processes within the seed that lead to germination.
Multiplexor
Multiplexor
Germination.
The toxins and harmful bacteria in the pollution stops or slows the germination process. Also the plant could still grow but turn out to be a bad or harmful product in the end.
It signals the end of a female's menstruating and end of fertility.
Germination conditions typically include moisture, oxygen, proper temperature, and sometimes light. Seeds need adequate water to soften the seed coat and activate enzymes for growth, oxygen for respiration to provide energy, suitable temperature for enzyme activity, and in some cases, light signals for the seeds to start growing.
The Closing Ceremony signals the ending of the Olympic Games.
Germination.