Stem cells directly produce adult tissues primarily through the process of differentiation. While mitosis, meiosis, and fertilization are processes related to cell division and reproduction, they do not specifically account for how stem cells develop into various types of adult tissues.
Explanation:
Stem cells are unique because they have the ability to differentiate into specialized cell types, which is crucial for forming the diverse tissues in our bodies. During differentiation, stem cells undergo specific changes that lead them to become specific cells, such as muscle cells, nerve cells, or blood cells. In contrast, mitosis is simply a method of cellular division that results in two identical daughter cells, and meiosis is involved in the production of gametes (sperm and eggs), not in the production of adult tissues.
Fertilization, on the other hand, is the union of sperm and egg, marking the beginning stage of development, but does not directly relate to how adult tissues are formed from stem cells. Therefore, the correct answer is c) differentiation.