An essential nutrient<span> is a </span>nutrient<span> that the body cannot synthesize on its own -- or not to an adequate amount -- and must be provided by the diet. These</span>nutrients<span> are necessary for the body to function properly. On the other the non-essential ones cannot be made inside the body so they are acquired from the food we eat.</span>
By there DNA. When when x and y have sex they send there gene into the offspring
Explanation: Electron microscopes are the most powerful type of microscope, capable of distinguishing even individual atoms. However, these microscopes cannot be used to image living cells because the electrons destroy the samples.
Answer:
By definition, tissues are absent from unicellular organisms. Even among the simplest multicellular species, such as sponges, tissues are lacking or are poorly differentiated. But multicellular animals and plants that are more advanced have specialized tissues that can organize and regulate an organism’s response to its environment.