Nutritional Requirements

Plants and animals are made up of cells. Growth and reproduction of plant or an animals generally means the growth and reproduction of the cell in its make up. Since all cells contains protoplasm and cell membrane, the nutrients they need for their activities, growth SNF reproduction are similar.

Note :  the nutritional needs of an amoeba would, off course , be very much less complex than that of a human being, just compare the organs a human has with the organelles of an amoeba! Again, the nutritional needs of specialized cells in an organism will vary according to their structural adaptations and functions. For example, the red blood cell needs iron for its function, while the cells in the skin do not.

    The major elements are those that are needed in large amounts, while the trace elements are needed in very small amounts (a few parts per million).

     Green plants get the elements carbon, hydrogen and oxygen from carbon dioxide and water, and the rest as mineral salts from their environment. Using these, they synthesize the organic materials that they need, mainly carbohydrates, proteins, lipids, vitamins and nucleic acids.

     Animals get all the essential elements from ready made food. This food, in turn , is made up of plant and / or animal parts and products. The main organic substance in food is carbohydrates, proteins and lipids. They are known as macro nutrients. They supply the elements carbon, hydrogen, oxygen,  nitrogen and phosphorus. The remaining essential elements are needed in smaller amounts. These , together with the trace elements and the vitamins, are usually known as macro nutrients. Vitamins are essential and organic substance that are needed by animals in trace amounts for the healthy functioning of their cells. Plants can synthesize vitamins in their cells.

    Lack of any essential nutrients in the diet of an organism affects its cells. For example, lack of iron in human diet means ref blood cells cannot function Properly. This cause anaemia a deficiency condition. In the case of green plants, the cells cannot synthesize chlorophyll. This affects their food making process. Deficiency is seen in the yellowing kg leaves and poor growth of the plant. Thus, we see that the direct effect of the organism. Eventually, the organism as a whole is affected and is said to suffer from a deficiency disease or condition.

    Too much nutrients may also harm an organism. For example, a person who eats too much carbohydrates and fats becomes obese. This is due to the formation and accumulation of fat storage cells in the body. A very high protein diet overworks the cells in the liver and kidney as they have to break down the excess nutrients and excrete them. This organs as a whole, become damaged causing early death. Excess of certain micro nutrient also has  toxic effects on the cells of a person.

    We can also observe the effect of too Mich minerals nutrients on plants, by adding a concentration solution of an inorganic fertilizer to a Potter plant. The ant wilts and dies as the strong salt solution causes the root hair cells to plasmolyse.