Which are sources of adult cells? check all that apply. A. bone marrow B. amniotic fluid C. brain D. gametes E. liver F. embryo

Adult stem cells have been identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. They are thought to reside in a specific area of each tissue (called a "stem cell niche "). So the answer is B.