Final answer:
Smooth muscle tissue and nucleus refer to components found within a cell. A cell is the basic structural and functional unit of all living organisms.
Step-by-step explanation:
Smooth muscle tissue and nucleus refer to components found within a cell. A cell is the basic structural and functional unit of all living organisms. It is the smallest unit of life that can replicate independently, and it contains various organelles including the nucleus. Smooth muscle tissue, which is found in the walls of various organs such as the digestive and respiratory tracts, is made up of smooth muscle cells.