Why are concentration gradients important to cells

A concentration gradient is the process of particles or solutes moving through a solution from areas of  greater particle concentration to areas of low particle concentration.

The importance of a concentration gradient is that it is what makes osmosis and diffusion to happen. If there were no gradient, there would be no movement of anything from high to low concentrations.  Because  cells are either hypertonic or hypotonic, nutrients and materials are able to flow either in or out of the cell and life is sustained. If all cells were isotonic, then there would be no flow of nutrients and materials and cells would not survive.  

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

this transfer is call conjunction