A plant's life cycle typically begins with a seed (except ferns, mosses, fungi and algae which start from spores). Depending on the type of plant a seed may be large or as small as a grain of sand. Each seed contains inside it's protective coating an embryo plant and a supply of stored food to start the embryo growing and sustain it until it is capable of making it's own food.
Seeds sprout or germinate when they feel ready. Certain conditions help them feel ready: moisture and warmth, light or absence of light, a period of dormancy, very high or very low temperatures. When the seed sprouts, the seed coat splits, a rootlet starts downward and a sprout bearing one or more seed leaves makes it's way towards the soil surface.Most plants have two seed leaves.
The first single root sent down by the seed begins to send out tiny white rootlets. It is their job to draw in the chemical substances needed for growth, and the water needed to carry these substances to the parts of the plant above the soil level.
As the plant grows, the roots grow too.They still function to serve water and nutrients to the plant, but can also store food. The entire root system also serves to anchor the plant in the soil.
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