Answer:
4) molecule, cell, organ system, population, ecosystem, biosphere
Explanation:
Various biomolecules such as carbohydrates, proteins, lipids, etc. together make the cells. Cells are the structural and functional units of life. A group of cells destined to perform specific functions makes tissues and various specific tissues together make an organ.
An organized group of tissues and organs that work cooperatively to perform a specialized set of functions is called an organ system. For example, the digestive system includes organs involved in the breakdown of nutrients.
A group of organisms of the same species that live in a defined geographic area at the same time make a population. Ecosystem refers to an interacting system including a biotic community and its nonliving, physical environment. The biosphere includes all of the parts of Earth where life forms exist and include the atmosphere, the hydrosphere and the lithosphere.
Your answer is D. untestable and open to change
I guess the stomach is held in place by a variety of Muscle cells, Epithelial cells, and connecting tissues; so the answer is: all of the above.