How To Sprout Seeds?

How seeds sprout in earth?

• y seeds sprout in(under the earth i.e. dug into) earth & not on(on the surface) earth?

• Answer:

  Some seeds do sprout on the surface, but the root (which is the first part of the plant to come out of the seed) has negative phototropism (that is, it grows _away_ from the light) and positive geotropism (it grows in the direction of the pull of gravity). Thus they end up inside the soil, even if they were on the surface initially. Some plants need dark to germinate; others don't grow unless there is some light (that assures future photosynthesis). Other necessary conditions are certain water and temperature levels; normally those factors are more stable within the soil than on the surface.