1) Light penetrates the water to a shallow depth, so plant organisms can exist only in the upper layers. 2) The density of the aquatic environment influences the streamlined body shape and strong muscles of fast moving animals. 3) The density of the environment lightens the weight of organisms and creates the ability to constantly be in the water column – plankton. 4) The presence of plankton makes possible the filtration type of nutrition for many animals.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.