Hypogeal Germination

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Germination is the process by which a plant begins growing from a seed. Two main types of seed germination include hypogeal and epigeal germination. In hypogeal germination, the cotyledons remain in the soil due to the elongation of epicotyl, and this type of germination is found in both monocotyledons and dicotyledons. In epigeal germination, the cotyledons emerge from the ground due to elongation of the hypocotyl. This type of germination is found only in dicotyledons, and is the type that sunflower seeds undergo (Kumar, n.d.).
Seeds contain embryonic tissue and, in most cases, a store of nutrient reserve, and these are protected by a seed coat. The first stage of germination is imbibition, wherein the seed takes in water so the contents
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If the temperature is not within a range specific to each seed species, it may cause damage to the seeds or cause them to become dormant (a state in which seeds are not able to germinate). Oxygen availability is important because seeds must be able to respire and engage in gas exchange in order to keep their embryonic tissue healthy, and this is not possible if oxygen is limited. Additionally, if water availability is insufficient, the seed will not be able to carry out imbibition so germination cannot occur. Ideal light conditions vary between seed species, but if the light conditions are not appropriate for a seed, it will not be able to reach its maximum growth potential.
Although the exact role of hydrogen peroxide in seed germination remains unclear, the general scientific consensus is that in plants it acts as a signaling molecule for a variety of biological processes. A signaling molecule is a molecule that transmits information between the cells of a plant and causes some type of process, reaction, or function to occur. In the case of hydrogen peroxide, it seems to play a role in signaling for, among other things, the regulation of seed dormancy. Hydrogen peroxide appears to signal for dormancy to be broken, causing germination to occur (Cooper,
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