Weil is less enthusiastic about white, or button, mushrooms, a species of mushroom that also includes Portobellos and criminis. âButton mushrooms do possess some health benefits, but not the general health benefits found in Asian mushrooms,â Weil says.
What sort of information do they encode, and how can this affect a cell's characteristics and activities? Some genes enable cells to make proteins needed for basic functions; dubbed housekeeping genes, they are active in many types of cells. Other genes, however, are inactive most of the time. Some genes play a role in early development of the embryo and are then shut down forever. Many genes encode proteins that are unique to a particular kind of cell and that give the cell its character - making a brain cell, say, different from a bone cell. A normal cell activates just the genes it needs at the moment and actively suppresses the rest.
Gene-the functional and physical unit of heredity passed from parent to offspring. Genes reside on chromosomes. If a gene is like a chapter in a book, the chromosome is the book itself. Proteins and RNA influence how an organism looks, how well its body metabolizes food and fights infection, and even how it behaves. The number of human genes is about 20,000-25,000. Different genes can vary in length and cover thousands of bases.