A seed needs water, oxygen, and proper temperature to germinate and grow into a plant; some seeds also require light (or darkness) to germinate.
Here's a more detailed breakdown:
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Water: Water is crucial for activating enzymes within the seed. These enzymes begin the process of breaking down stored food reserves, providing the energy the developing seedling needs. Water also softens the seed coat, allowing the emerging root and shoot to break through.
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Oxygen: Seeds respire (breathe), just like animals. They need oxygen to fuel the metabolic processes involved in germination. Oxygen is used to break down stored food and release energy for growth.
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Proper Temperature: Each type of seed has an optimal temperature range for germination. Temperature affects the rate of enzyme activity; too cold, and the enzymes work too slowly; too hot, and the enzymes can be denatured (destroyed).
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Light (for some seeds): While not all seeds need light, some require it to trigger germination. Light-sensitive seeds contain pigments (like phytochrome) that detect light and initiate the germination process. Conversely, other seeds require darkness to germinate; light can actually inhibit their germination.
In summary, successful seed germination depends on having the right combination of environmental factors. Without sufficient water, oxygen, or the appropriate temperature, a seed will remain dormant. For certain species, light or the absence of light is also an essential factor.
