</span>An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system. <span> </span>
It is very important to control the conditions of an experiment because FAILURE TO DO THIS WILL MAKE THE RESULTS OF THE EXPERIMENT INVALID.
A controlled experiment refers to an experiment that is conducted under controlled conditions. Conducting experiments under controlled conditions helps scientists to minimize the changes in all other variables with the exception of the ones been tested.
Basically, the difference between natural and organic stems from an official designation set forth by the United States Department of Agriculture (USDA) for organic foods. In 2000, the <span>USDA </span>published its official positionon organic foods and made its production a matter for strict supervision and legal regulation. While there are several criteria for organic foods, in order to be labeled "organic," food must have been grown without the use of synthetic fertilizers and pesticides (with some rare exceptions), antibiotics, irradiation, genetic engineering, or growth hormones. According to the <span>USDA, </span>"organic" is a labeling term that denotes products that are produced under the authority of the Organic Foods Production Act. Additionally, organic farming involves growing systems that enhance biodiversity, biological cycles and soil biological activity.
On the other hand, natural foods have no legal or federal supervision at all, and are not defined by any law or criteria. While the <span>USDA </span>does require that products list their ingredients in descending order of concentration, there is no official stipulation for the amount of natural ingredients a food must contain to be deemed as such. A food labeled "natural" is usually considered to contain less preservatives and chemical additives than other kinds of processed foods, though since there is no way to legally supervise the product, no sure answer may be set forth.
