How does the amount of matter in a single seed compare to the amount of matter in the plant that has grown for five weeks

plants absorb water from the soil by osmosis. root hair cells are adapted for this by having a large surface area to speed up osmosis. the absorbed water is transported through the roots to the rest of the plant where it is used for different purposes: it transports dissolved minerals around the plant.

the species living around the vents are especially good at dispersal.  

deep-sea vent originates on the floor of the ocean when seawater circulates through hot volcanic rocks, usually situated where the new oceanic crust is being produced.  

biological dispersal refers to the movement of species from their location of birth to their site of breeding, or from breeding site to another. similarly, the oceanic dispersal refers to the movement of the species from one land mass to another by sea crossing.