Organisms that live in water are not totally independent of soil as a resource. These organisms depend on aquatic plants for food and other substances. These aquatic plants in turn require minerals for their sustenance. These minerals are carried to waterbodies from soil by rivers, rainwater etc.
The time period being referred to is the sensitive period. This time period is also referred to as the critical period. The importance of a critical period is such that it must involve certain stimuli from which an organisms learns and acquires traits. If some of these stimuli are not present in the critical period, the organism has difficulty acquiring the trait or skill, and may even find it to be impossible to learn the skill.
The correct answer is - underwater mountain ranges.
The mid-ocean ridges are actually underwater mountain ranges, which usually are very long, in fact the longest mountain range on Earth is created on the divergent boundary between the Eurasian and North American tectonic plates and between the African and South American tectonic plates. At the divergent tectonic boundaries we have the creation of new crust which rises from the mantle and fills in the gap between the tectonic plates. Because of the big amount of magma and high pressure, very big and long underwater mountain ranges are formed.
The nucleus resembles the brains function.
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